Page 3 SAFETY PRECAUTIONS (Be sure to read these instructions before use.) Before using this product, please read this manual and the relevant manuals introduced in this manual carefully and pay full attention to safety to handle the product correctly. The instructions given in this manual are concerned with this product. For the safety instructions of the programmable controller system, please read the CPU module user's manual.
Page 4 [INSTALLATION PRECAUTIONS] CAUTION Use the programmable controller in the operating environment that meets the general specifications of this manual. Using the programmable controller in any other operating environments may cause electric shocks, fires or malfunctions, or may damage or degrade the product. Fully insert the protection on the bottom of the module into the hole in the base unit and press the module into position.
Page 5 [SETUP AND MAINTENANCE PRECAUTIONS] CAUTION Please read this manual thoroughly and confirm the safety before starting online operations (especially, program modifications, forced outputs, and operating status modifications), which are performed by connecting the GX Developer via the MELSECNET network system to a running CPU module of other station.
Page 6 This manual confers no industrial property rights or any rights of any other kind, nor does it confer any patent licenses. Mitsubishi Electric Corporation cannot be held responsible for any problems involving industrial property rights which may occur as a result of using the contents noted in this manual.
Page 7: Table Of Contents
INTRODUCTION Thank you for choosing the Mitsubishi MELSEC-A Series of General Purpose Programmable Controllers. Before using the equipment, please read this manual carefully to develop full familiarity with the functions and performance of the A series programmable controller you have purchased, so as to ensure correct use.
Page 8 4.2.1 System configuration •••••••••••••••••••••••••••••••••••••••••••••••••••••••••••••••••••••••••••••••••••• 4 - 10 4.2.2 Precautions when using data link ••••••••••••••••••••••••••••••••••••••••••••••••••••••••••••••••••••• 4 - 11 4.2.3 System devices••••••••••••••••••••••••••••••••••••••••••••••••••••••••••••••••••••••••••••••••••••••••••• 4 - 13 Data Link System when the Second Tier is MELSECNET/B and the Third Tier is MELSECNET•••••••••••••••••••••••••••••••••••••••••••••••••••••••••••••••••••••••••••••••••••••••••••••••••••• 4 - 19 4.3.1 System configuration ••••••••••••••••••••••••••••••••••••••••••••••••••••••••••••••••••••••••••••••••••••...
Page 9 DATA LINK SETTINGS 7 - 1 to 7 - 85 Data Link Settings Overview •••••••••••••••••••••••••••••••••••••••••••••••••••••••••••••••••••••••••••••••••••7 - 1 Setting of the Number of Modules•••••••••••••••••••••••••••••••••••••••••••••••••••••••••••••••••••••••••••••7 - 2 Network Refresh Parameters ••••••••••••••••••••••••••••••••••••••••••••••••••••••••••••••••••••••••••••••••••7 - 4 Link Parameters •••••••••••••••••••••••••••••••••••••••••••••••••••••••••••••••••••••••••••••••••••••••••••••••• 7 - 11 7.4.1 Link parameters to be set for the MELSECNET mode ••••••••••••••••••••••••••••••••••••••••••• 7 - 11 7.4.2 Link parameters to be set for the MELSECNET mode ••••••••••••••••••••••••••••••••••••••••...
Page 10 8.5.2 Connecting shielded twisted pair cables••••••••••••••••••••••••••••••••••••••••••••••••••••••••••••• 8 - 15 Startup Procedure •••••••••••••••••••••••••••••••••••••••••••••••••••••••••••••••••••••••••••••••••••••••••••••• 8 - 16 Self-diagnostics Test••••••••••••••••••••••••••••••••••••••••••••••••••••••••••••••••••••••••••••••••••••••••••• 8 - 17 8.7.1 Self-loopback test •••••••••••••••••••••••••••••••••••••••••••••••••••••••••••••••••••••••••••••••••••••••• 8 - 17 8.7.2 Station to station test •••••••••••••••••••••••••••••••••••••••••••••••••••••••••••••••••••••••••••••••••••• 8 - 19 8.7.3 Forward loop test and reverse loop test •••••••••••••••••••••••••••••••••••••••••••••••••••••••••••• 8 - 21 PROGRAMMING 9 - 1 to 9 - 52 Precautions for Creating Programs •••••••••••••••••••••••••••••••••••••••••••••••••••••••••••••••••••••••••••9 - 1...
Page 11 (Sold separately) COMPLIANCE WITH THE EMC AND LOW VOLTAGE DIRECTIVES When incorporating the Mitsubishi programmable controller into other machinery or equipment and ensuring compliance with the EMC and low voltage directives, refer to Chapter 3 "EMC and Low Voltage Directives" of the User's Manual (Hardware) included with the CPU module or base unit used.
Page 12: Overview
MELSECNET data link system is a system to connect link modules via optical fiber cable or coaxial cable and to control them. The system can be configured in the MELSEC-A series. The only difference between a system using optical fiber cable and a system using coaxial cable is a distance between link modules.
Page 13: Contents Of This Manual
OVERVIEW Contents of This Manual This manual explains the MELSECNET data link system and the MELSECNET/B data link system. The MELSECNET data link system is explained in Chapter 2 and the MELSECNET/B data link system is explained in Chapter 3. Other chapters explain both systems.
Page 14: Basic Information About Data Link Systems
MELSECNET mode MELSECNET MELSECNET/B MELSECNET MELSECNET MELSECNET MELSECNET MELSECNET MELSECNET Operating Mode mode composite mode mode mode composite mode mode OVERVIEW Applicability Basic Information about Data Link Systems This section gives the basic information for using the MELSECNET and the MELSECNET/ B data link systems.
Page 15: Outline Of The Melsecnet And Melsecnet/B Data Link Systems
1.2.2 Outline of the MELSECNET and MELSECNET/B data link systems Use a MELSEC-A series programmable controller CPU to establish a data link system via optical fiber, coaxial or twisted-wire pair cables. The MELSECNET data link system is a system to connect link modules via optical fiber cables or coaxial cables.
Page 16: Differences Between The Melsecnet And Melsecnet/B Data Link Systems
OVERVIEW 1.2.3 Differences between the MELSECNET and MELSECNET/B data link systems The following table shows differences between the MELSECNET and MELSECNET/B data link systems. Table 1.1 Differences between the MELSECNET data link system and MELSECNET/B data link system MELSECNET data link system MELSECNET/B data link system Optical data link system Item...
Page 17: Differences Among The Melsecnet Mode, Melsecnet Mode, And Melsecnet
OVERVIEW 1.2.4 Differences among the MELSECNET mode, MELSECNET mode, and MELSECNET composite mode The data link system has the MELSECNET mode, the MELSECNET mode, or the MELSECNET composite mode. In the MELSECNET mode, the data link system operates within the range of B/W0 to 3FF regardless of the link module used for the master station.
Page 18 OVERVIEW Link modules that can be used as the local station (Refer to Table 1.2 for the link module model name.) (a) MELSECNET mode MELSECNET mode- and MELSECNET mode-compatible data link modules (b) MELSECNET mode MELSECNET mode-compatible data link modules (c) MELSECNET composite mode MELSECNET mode- and MELSECNET...
Page 19 OVERVIEW Link parameter types and the number of link points per station (a) MELSECNET mode 1) Link parameter is only one type. 2) Maximum number of link points per station Master station and local station : 1024 bytes/station Remote I/O station : 512 bytes/station (I/O is 512 points of X/Y0 to 1FF per station) (b) MELSECNET...
Page 20: Composite Mode
OVERVIEW Table 1.2 MELSECNET ( ) Data Link Function Overview Operation mode MELSECNET data link system Item MELSECNET MELSECNET mode MELSECNET mode composite mode A0J2HCPUP21/R21 AnNCPUP21/R21 AnNCPUP21-S3 A2NCPUP21-S4 AnACPUP21/R21 AnACPUP21/R21 AnACPUP21-S3 AnACPUP21-S3 A2ACPUP21-S4 A2ACPUP21-S4 AnACPU+AJ71AP21(S3)/R21 Data link modules that AnACPU+AJ71AP21(S3)/R21 AnUCPU+AJ71AP21(S3)/R21 can be used as a master station AnUCPU+AJ71AP21(S3)/R21...
Page 21 OVERVIEW Table 1.2 MELSECNET ( ) Data Link Function Overview (Continued) Operation mode MELSECNET/B data link system MELSECNET MELSECNET mode MELSECNET mode composite mode AnNCPU+AJ71AT21B AnACPU+AJ71AT21B AnACPU+AJ71AT21B AnUCPU+AJ71AT21B AnUCPU+AJ71AT21B QnACPU+AJ71AT21B QnACPU+AJ71AT21B AnSCPU+A1SJ71AT21B AnASCPU+A1SJ71AT21B AnASCPU+A1SJ71AT21B QnASCPU+A1SJ71AT21B QnASCPU+A1SJ71AT21B A80BD-A2USH-S1+A1SJ71AT21B A80BD-A2USH-S1+A1SJ71AT21B AnNCPU+AJ71AT21B AnACPU+AJ71AT21B AnACPU+AJ71AT21B AnUCPU+AJ71AT21B AnUCPU+AJ71AT21B...
Page 22: Differences Between Qcpu And A/Qnacpu Local Stations
OVERVIEW 1.2.5 Differences between QCPU and A/QnACPU local stations When using an QCPU local station This module replaces or adds a part of the existing MELSECNET ( ) data link system to QCPU. Master station QCPU MELSECNET( ) Local station Local station Differences between QCPU and A/QnACPU local stations When replacing an A/QnACPU local station with a QCPU one, pay attention to the...
Page 23 OVERVIEW Table 1.3 Differences between QCPU and A/QnACPU local stations (Continued) Description Item QCPU local station A/QnACPU local station Handles the received instruction with the sequence program. The system handles the received instruction. If the LRDP/LWTP instruction is received LRDP/LWTP instruction (The program for receiving LRDP/LWTP instruction is not when the CPU module is in STOP status, receive processing...
Page 24: Applicable Link Modules And General Names
OVERVIEW Applicable Link Modules and General Names 1.3.1 Applicable link modules This manual explains the link modules shown below. The link modules compatible with MELSECNET mode also support the MELSECNET mode. MELSECNET data link system CPU modules (a) Link modules compatible with MELSECNET mode A0J2HCPUP21/R21 A1NCPUP21/R21 A1NCPUP21-S3...
Page 25 OVERVIEW MELSECNET/B data link system The following link modules are installed to a base unit. (a) Link module compatible with MELSECNET mode (Installed in the CPU slot) A1SJ72T25B (for remote I/O station) AJ72T25B (for remote I/O station) (b) Link module compatible with MELSECNET mode (Installed in an I/O slot) A1SJ71AT21B (for master station/local station) AJ71AT21B (for master station/local station)
Page 26: General Names Of Cpu Modules
OVERVIEW 1.3.2 General names of CPU modules This manual describes CPU modules using the following generic names. AnNCPU AnNCPU is general name for the following link modules: 1) A1NCPU 3) A2NCPU-S1 2) A2NCPU 4) A3NCPU AnACPU AnACPU is general name for the following link modules: 1) A2ACPU 3) A3ACPU 2) A2ACPU-S1...
Page 27 OVERVIEW (10) AnACPUP21/R21 AnACPUP21/R21 is general name for the following link modules: 1) A2ACPUP21/R21 4) A2ACPUP21-S4 2) A2ACPUP21/R21-S1 5) A3ACPUP21/R21 3) A2ACPUP21-S3 6) A3ACPUP21-S3 (11) QCPU QCPU is general name for the following CPU modules: 1) Q02CPU 4) Q12HCPU 2) Q02HCPU 5) Q25HCPU 3) Q06HCPU 1 - 16...
Page 28: Two-Tier System In The Melsecnet Data Link System
TWO-TIER SYSTEM IN THE MELSECNET DATA LINK SYSTEM TWO-TIER SYSTEM IN THE MELSECNET DATA LINK SYSTEM This section describes the MELSECNET data link system. Outline of the MELSECNET Data Link System 2.1.1 Configuration of the data link system The MELSECNET data link system connects link modules via optical fiber or coaxial cables.
Page 29 TWO-TIER SYSTEM IN THE MELSECNET DATA LINK SYSTEM REMARK Master stations, local stations, and remote I/O stations are expressed in the following symbols. • Master station....M • Local station....L (Local station No. n: Ln) • Remote I/O station..R (remote I/O station No. n: Rn) 2 - 2...
Page 30: Features Of The Data Link System
TWO-TIER SYSTEM IN THE MELSECNET DATA LINK SYSTEM 2.1.2 Features of the data link system The following describes features of MELSECNET data link system. Cyclic transmission function The cyclic transmission is a function to periodically communicate data between a master station and slave stations (local stations and remote I/O stations). Either 1 : n or 1 : 1 data communications are enabled by the cyclic transmission.
Page 31 TWO-TIER SYSTEM IN THE MELSECNET DATA LINK SYSTEM Transient transmission function The transient transmission function reads/writes data from/to a device in a local station by the master station programmable controller CPU or communicates data between a peripheral device connected to a programmable controller CPU and a programmable controller CPU in another station.
Page 32 TWO-TIER SYSTEM IN THE MELSECNET DATA LINK SYSTEM Improved RAS (Reliability, Availability, Serviceability) functions (a) Loopback function If a cable breaks or the power supply to a slave station is turned off, the affected slave station is disconnected from the data link so that normal link operations are able to continue for other stations.
Page 33 TWO-TIER SYSTEM IN THE MELSECNET DATA LINK SYSTEM Using MELSECNET mode and MELSECNET mode-compatible modules in the same network The link module which can be connected to MELSECNET data link system includes the MELSECNET mode-compatible link module and the MELSECNET mode- compatible link module.
Page 34: Melsecnet Data Link System
TWO-TIER SYSTEM IN THE MELSECNET DATA LINK SYSTEM MELSECNET Data Link System 2.2.1 Overall configuration Two-tier system In a two-tier system, up to 64 stations (local and remote I/O stations) can be connected to the master station with optical fiber cable or coaxial cable. In a two-tier system, a master station is referred to as "master station"...
Page 35 TWO-TIER SYSTEM IN THE MELSECNET DATA LINK SYSTEM (b) The following table shows the configurations of the master station/local station and the remote I/O station. Master stations / Local stations Type of Remote I/O station cable CPU module with a link function CPU module + link module Optical fiber cable...
Page 36: Precautions When Operating The Data Link System
TWO-TIER SYSTEM IN THE MELSECNET DATA LINK SYSTEM 2.2.2 Precautions when operating the data link system The following describes the precautions for performing data link. Optical fiber cable and coaxial cable cannot be mixed in the same loop. The same type of cable must be used for links within the same loop of the two-tier system.
Page 37: Applicable Modules
TWO-TIER SYSTEM IN THE MELSECNET DATA LINK SYSTEM 2.2.3 Applicable modules The following describes link modules which can be used in the MELSECNET. Data link module using optical fiber cable The data link modules that can be connected with optical fiber cable are listed in Table 2.2.
Page 38 TWO-TIER SYSTEM IN THE MELSECNET DATA LINK SYSTEM REMARK (1) The M, L and R stations in Table 2.2 indicate the following stations. a) M station..Master station b) L station... Local station c) R station... Remote I/O station (2) *1: Applicable only when used in combination with the A2US(H)CPU(S1) or Q2AS(H)CPU(S1).
Page 39 TWO-TIER SYSTEM IN THE MELSECNET DATA LINK SYSTEM Data link module using coaxial cable The data link modules that can be connected with coaxial cable are listed in Table 2.3. Table 2.3 Data Link Modules Connectable with Coaxial Cable : Applicable Applicable system Two-tier system Module...
Page 40 TWO-TIER SYSTEM IN THE MELSECNET DATA LINK SYSTEM MEMO 2 - 13...
Page 41: Two-Tier System In The Melsecnet/B Data Link System
TWO-TIER SYSTEM IN THE MELSECNET/B DATA LINK SYSTEM TWO-TIER SYSTEM IN THE MELSECNET/B DATA LINK SYSTEM This section describes the MELSECNET/B data link system. Outline of the MELSECNET/B Data Link System 3.1.1 Configuration of the data link system The MELSECNET/B data link system is a system to connect link modules using shielded twisted pair cable.
Page 42: Features Of The Data Link System
TWO-TIER SYSTEM IN THE MELSECNET/B DATA LINK SYSTEM 3.1.2 Features of the data link system The features of the MELSECNET/B data link system are described below. Cyclic transmission function The cyclic transmission is a function to periodically communicate data between a master station and slave stations (local stations and remote I/O stations) Either 1 : n or 1 : 1 data communications are enabled by the cyclic transmission function.
Page 43 TWO-TIER SYSTEM IN THE MELSECNET/B DATA LINK SYSTEM Transient transmission function The transient transmission function (a) reads/writes data from/to a device in a local station by using a master station programmable controller CPU, and (b) communicates data between a peripheral device connected to a programmable controller CPU and a programmable controller CPU in another station.
Page 44 TWO-TIER SYSTEM IN THE MELSECNET/B DATA LINK SYSTEM REMARK (1)*1..When the AnACPU(P21/R21), AnUCPU or A2US(H)CPU(S1) is used, the LRDP/LWTP/RFRP/RTOP instructions of the dedicated instructions can also be used. (For details of the LRDP/LWTP/RFRP/RTOP instructions, refer to the AnACPU/AnUCPU Programming Manual (Dedicated Instructions) IB- 66251.) When the QnACPU, Q2AS(H)CPU(S1) is used, the ZNRD/ZNWR/ RFRP/RTOP instructions of the data link instructions can also be used.
Page 45: Melsecnet/B Data Link System
TWO-TIER SYSTEM IN THE MELSECNET/B DATA LINK SYSTEM MELSECNET/B Data Link System 3.2.1 Overall configuration Two-tier system The two-tier system is a system to connect up to 31 local stations and remote I/O stations to a master station via shielded twisted pair cables. In a two-tier system, a master station is referred to as "master station"...
Page 46: Precautions When Operating The Data Link System
TWO-TIER SYSTEM IN THE MELSECNET/B DATA LINK SYSTEM 3.2.2 Precautions when operating the data link system The following describes the precautions for performing data link. Number of link device points for one station Note that the number of link device (X, Y, B, W) points that can be used at a local station and a remote I/O station is limited.
Page 47: System Devices
TWO-TIER SYSTEM IN THE MELSECNET/B DATA LINK SYSTEM 3.2.3 System devices Table 3.2 shows the link modules that can be used in the MELSECNET/B Data Link System. Table 3.2 List of link modules : Available Applicable system Two-tier system Description MELSEC MELSECNET Link module...
Page 48 TWO-TIER SYSTEM IN THE MELSECNET/B DATA LINK SYSTEM Table 3.2 List of link modules (Continued) : Available Applicable system Two-tier system Description MELSEC MELSECNET Link module CPU module Remarks MELSECNET composite mode mode mode Program capacity Number of I/O points Module for remote I/O stations, which is to AJ72T25B be mounted to the following base unit:...
Page 49: Composition Of A Three-Tier System
COMPOSITION OF A THREE-TIER SYSTEM COMPOSITION OF A THREE-TIER SYSTEM In a three-tier system, a local station in the second tier is used as a master station for the third tier and connects with the slave stations. MELSECNET data link system and MELSECNET/B data link system can be used for the second and third tiers.
Page 50: Three-Tier System Using The Melsecnet Data Link System
COMPOSITION OF A THREE-TIER SYSTEM Three-Tier System Using the MELSECNET Data Link System When the second and third tiers are configured with MELSECNET data link system, connect the stations using optical fiber cables or coaxial cables. (a) Up to 64 local and remote I/O stations can be connected to a master station for the second tier.
Page 51 COMPOSITION OF A THREE-TIER SYSTEM In the three-tier system, optical fiber cables and coaxial cables can be used together for the second and third tiers. Combinations of the optical fiber cables and coaxial cables for each tier are shown below. POINT (1) In MELSECNET data link system, up to three tiers can be configured.
Page 52: Precautions When Operating Data Link System
COMPOSITION OF A THREE-TIER SYSTEM 4.1.2 Precautions when operating data link system This section explains precautions for three-tier system using MELSECNET data link. Setting link parameters In the three-tier system, setting link parameters to CPU modules for the master stations in the second and third tiers is required. For link parameter setting, refer to Section 5.3.7 and Chapter 7.
Page 53 COMPOSITION OF A THREE-TIER SYSTEM (b) For the CPU module any of the AnUCPU, A2ASCPU(S1), A2US(H)CPU(S1), QnACPU, and Q2AS(H)CPU(S1) Up to two of the following link modules (one as a master station and the other as a local station) can be used with a CPU module. (The two modules cannot be used only for master stations or local stations.) AJ71AP21 AJ71AP21-S3...
Page 54: System Devices
COMPOSITION OF A THREE-TIER SYSTEM 4.1.3 System devices Table 4.1 Link modules available for the three-tier system : Available Applicable system MELSECNET data link Second tier Third tier Module Model Remarks MELSEC MELSECNET MELSEC MELSECNET MELSECNET MELSECNET composite composite mode mode mode mode...
Page 55 COMPOSITION OF A THREE-TIER SYSTEM Table 4.1 Link modules available for the three-tier system (Continued) : Available Applicable system MELSECNET data link Second tier Third tier Module Model Remarks MELSEC MELSECNET MELSEC MELSECNET MELSECNET MELSECNET composite composite mode mode mode mode mode mode...
Page 56 COMPOSITION OF A THREE-TIER SYSTEM Table 4.1 Link modules available for the three-tier system (Continued) : Available Applicable system MELSECNET data link Second tier Third tier Module Model Remarks MELSEC MELSECNET MELSEC MELSECNET MELSECNET MELSECNET composite composite mode mode mode mode mode mode...
Page 57 COMPOSITION OF A THREE-TIER SYSTEM Table 4.1 Link modules available for the three-tier system (Continued) : Available Applicable system MELSECNET data link Second tier Third tier Module Model Remarks MELSEC MELSECNET MELSEC MELSECNET MELSECNET MELSECNET composite composite mode mode mode mode mode mode...
Page 58: Data Link System When The Second Tier Is Melsecnet And The Third Tier Is
COMPOSITION OF A THREE-TIER SYSTEM Data Link System when the Second Tier is MELSECNET and the Third Tier is MELSECNET/B In the system that the second tier is a MELSECNET data link system and the third tier is a MELSECNET/B data link system, the second tier is connected with optical fiber cables or coaxial cables, and the third tier is connected with shielded twisted pair cables.
Page 59 COMPOSITION OF A THREE-TIER SYSTEM 4.2.2 Precautions when using data link This section explains precautions for configuring a three-tier system. Setting link parameters In the three-tier system, setting link parameters to CPU modules for the master stations in the second and third tiers is required. For link parameter setting, refer to Section 5.3.7 and Chapter 7.
Page 60 COMPOSITION OF A THREE-TIER SYSTEM Restriction on use of link modules (a) For the CPU module other than the AnUCPU, A2ASCPU(S1), A2USHCPU-S1, QnACPU, and Q2AS(H)CPU(S1) Only one of the following link modules can be used with a CPU module. When configuring the three-tier system, use a CPU module having a link function with any of the following link modules.
Page 61 COMPOSITION OF A THREE-TIER SYSTEM 4.2.3 System devices Table 4.2 Link modules available for the three-tier system : Available Applicable system MELSECNET data link MELSECNET/B data link Second tier Third tier MELSEC MELSECNET MELSEC MELSECNET Module Model Remarks MELSECNET MELSECNET composite composite mode...
Page 62 COMPOSITION OF A THREE-TIER SYSTEM Table 4.2 Link modules available for the three-tier system (Continued) : Available Applicable system MELSECNET data link MELSECNET/B data link Second tier Third tier MELSEC MELSECNET MELSEC MELSECNET Module Model Remarks MELSECNET MELSECNET composite composite mode mode mode...
Page 63 COMPOSITION OF A THREE-TIER SYSTEM Table 4.2 Link modules available for the three-tier system (Continued) : Available Applicable system MELSECNET data link MELSECNET/B data link Second tier Third tier MELSEC MELSECNET MELSEC MELSECNET Module Model Remarks MELSECNET MELSECNET composite composite mode mode mode...
Page 64 COMPOSITION OF A THREE-TIER SYSTEM Table 4.2 Link modules available for the three-tier system (Continued) : Available Applicable system MELSECNET data link MELSECNET/B data link Second tier Third tier MELSEC MELSECNET MELSEC MELSECNET Module Model Remarks MELSECNET MELSECNET composite composite mode mode mode...
Page 65 COMPOSITION OF A THREE-TIER SYSTEM Table 4.2 Link modules available for the three-tier system (Continued) : Available Applicable system MELSECNET data link MELSECNET/B data link Second tier Third tier MELSEC MELSECNET MELSEC MELSECNET Module Model Remarks MELSECNET MELSECNET composite composite mode mode mode...
Page 66 COMPOSITION OF A THREE-TIER SYSTEM Table 4.2 Link modules available for the three-tier system (Continued) : Available Applicable system MELSECNET data link MELSECNET/B data link Second tier Third tier MELSEC MELSECNET MELSEC MELSECNET Module Model Remarks MELSECNET MELSECNET composite composite mode mode mode...
Page 67 COMPOSITION OF A THREE-TIER SYSTEM Data Link System when the Second Tier is MELSECNET/B and the Third Tier is MELSECNET In the system that the second tier is a MELSECNET/B data link system and the third tier is a MELSECNET data link system, the second tier is connected with shielded twisted pair cables, and the third tier is connected with optical fiber cables or coaxial cables.
Page 68 COMPOSITION OF A THREE-TIER SYSTEM 4.3.2 Precautions when operating the data link system This section explains precautions for configuring a three-tier system. Setting link parameters In the three-tier system, setting link parameters to CPU modules for the master stations in the second and third tiers is required. For link parameter setting, refer to Section 5.3.7 and Chapter 7.
Page 69 COMPOSITION OF A THREE-TIER SYSTEM (b) For the CPU module any of the AnUCPU, A2ASCPU(S1), A2USHCPU-S1, QnACPU, and Q2AS(H)CPU(S1) Up to two of the following link modules (one as a master station and the other as a local station) can be used with a CPU module. (The two modules cannot be used only for master stations or local stations.) [For local station] AJ71AP21...
Page 70 COMPOSITION OF A THREE-TIER SYSTEM 4.3.3 System devices Table 4.3 Link modules available for the three-tier system : Available Applicable system MELSECNET/B data link MELSECNET data link Second tier Third tier MELSEC MELSECNET MELSEC MELSECNET Module Model Remarks MELSECNET MELSECNET composite composite mode...
Page 71 COMPOSITION OF A THREE-TIER SYSTEM Table 4.3 Link modules available for the three-tier system (Continued) : Available Applicable system MELSECNET/B data link MELSECNET data link Second tier Third tier MELSEC MELSECNET MELSEC MELSECNET Module Model Remarks MELSECNET MELSECNET composite composite mode mode mode...
Page 72 COMPOSITION OF A THREE-TIER SYSTEM Table 4.3 Link modules available for the three-tier system (Continued) : Available Applicable system MELSECNET/B data link MELSECNET data link Second tier Third tier MELSEC MELSECNET MELSEC MELSECNET Module Model Remarks MELSECNET MELSECNET composite composite mode mode mode...
Page 73 COMPOSITION OF A THREE-TIER SYSTEM Table 4.3 Link modules available for the three-tier system (Continued) : Available Applicable system MELSECNET/B data link MELSECNET data link Second tier Third tier MELSEC MELSECNET MELSEC MELSECNET Module Model Remarks MELSECNET MELSECNET composite composite mode mode mode...
Page 74 COMPOSITION OF A THREE-TIER SYSTEM Table 4.3 Link modules available for the three-tier system (Continued) : Available Applicable system MELSECNET/B data link MELSECNET data link Second tier Third tier MELSEC MELSECNET MELSEC MELSECNET Module Model Remarks MELSECNET MELSECNET composite composite mode mode mode...
Page 75 COMPOSITION OF A THREE-TIER SYSTEM Three-Tier System using the MELSECNET/B Data Link System When the second and third tiers are configured with MELSECNET/B data link system, connect the stations using shielded twisted pair cables. (a) Up to 31 local and remote I/O stations can be connected to a master station for the second tier.
Page 76 COMPOSITION OF A THREE-TIER SYSTEM 4.4.2 Precautions when using data link This section explains precautions for configuring a three-tier system. Setting link parameters In the three-tier system, setting link parameters to CPU modules for the master stations in the second and third tiers is required. For link parameter setting, refer to Section 5.3.7 and Chapter 7.
Page 77 COMPOSITION OF A THREE-TIER SYSTEM 4.4.3 System devices Table 4.4 Link modules available for the three-tier system : Available Applicable system MELSECNET/B data link Second tier Third tier MELSEC MELSECNET MELSEC Module Model MELSECNET Remarks MELSECNET MELSECNET composite composite mode mode mode mode...
Page 78 COMPOSITION OF A THREE-TIER SYSTEM Table 4.4 Link modules available for the three-tier system (Continued) : Available Applicable system MELSECNET/B data link Second tier Third tier MELSEC MELSECNET MELSEC MELSECNET Module Model Remarks MELSECNET MELSECNET composite composite mode mode mode mode mode mode...
Page 79 MELSECNET mode MELSECNET MELSECNET/B MELSECNET MELSECNET MELSECNET MELSECNET MELSECNET MELSECNET Operating Mode mode composite mode mode mode composite mode mode SPECIFICATIONS Applicability SPECIFICATIONS This chapter describes the general specifications of the data link system and the performance specifications and functions of the link modules. General Specifications This section describes the general specifications of the data link system.
Page 80: Melsecnet/B
SPECIFICATIONS Performance Specifications The following shows the performance specifications of the data link system. Table 5.2 Performance specifications MELSECNET data link system Optical data link system Item MELSECNET MELSECNET MELSECNET mode mode composite mode Up to the maximum I/O points allowed for master station CPU module *2 Input (X) Max.
Page 81 MELSECNET mode MELSECNET MELSECNET/B MELSECNET MELSECNET MELSECNET MELSECNET MELSECNET MELSECNET Operating Mode mode composite mode mode composite mode mode mode SPECIFICATIONS Applicability Table 5.2 Performance specifications (Continued) MELSECNET data link system MELSECNET/B data link system Coaxial cable data link Shielded twisted pair cable data link system MELSECNET MELSECNET MELSECNET...
Page 82: Functions
SPECIFICATIONS Functions The following shows the functions of the data link system. Table 5.3 List of data link system functions Description Item MELSECNET data link system (1) Function to periodically communicate data between the master station and the slave stations (local station and remote I/O statiton).
Page 83 MELSECNET mode MELSECNET MELSECNET/B MELSECNET MELSECNET MELSECNET MELSECNET MELSECNET MELSECNET Operating Mode mode composite mode mode composite mode mode mode SPECIFICATIONS Applicability Table 5.3 List of data link system functions (Continued) Description Reference section MELSECNET/B data link system Section 5.3.1 Section 5.3.2 Section 5.3.3 Section 5.3.4...
Page 84: Cyclic Transmission Function
MELSECNET mode MELSECNET MELSECNET/B MELSECNET MELSECNET MELSECNET MELSECNET MELSECNET MELSECNET Operating Mode mode composite mode mode mode composite mode mode SPECIFICATIONS Applicability 5.3.1 Cyclic transmission function The cyclic transmission function is a function to periodically communicate data between the master station and the slave stations (local station or remote I/O station). The cyclic transmission function includes the following two communications.
Page 85 SPECIFICATIONS (b) Communication between the master station and a local station 1) Communicates data between the master station and a local station using some of I/O points in the master station and local stations for the data link. (Communication between local stations or communication between a local station and a remote I/O station is not possible.) 2) As for communication between the master station and a local station, the sender uses outputs (Y), and receiver uses inputs (X).
Page 86 SPECIFICATIONS Communication between the master station and all local stations Link relays (B) and link registers (W) are used for communication between the master station and a local station or communication between local stations. Link relays (B) and link registers (W) are used by the master station and all local stations in common.
Page 87 SPECIFICATIONS Master station (M) Local station No. 1 (L1) Local station No. 2 (L2) Local station No. 3 (L3) REMARK To simplify the example, the same number is assigned to link relays (B) and link registers (W). In actual use, the number can be separately assigned to link relays (B) and link registers (W).
Page 88 SPECIFICATIONS (b) Three-tier system configuration 1) In the configuration of the three-tier system, the link parameters are set in the master station for the second tier and the master station for the third tier. 2) The master station and local stations for the second tier (including the master station for the third tier) can read the range assigned by the link parameters of the master station for the second tier.
Page 89 SPECIFICATIONS Master station (M) for the second tier 1) The M station writes data to the devices in the B/W0 to FF range and sends it to the other stations. 2) The M station can receive data written to the devices in the B/W100 to 37F range by other stations.
Page 90 SPECIFICATIONS Local station No. 2 (Master station (L2/m) for third tier-2) 1) The L2/m station writes data to the devices in the B/W200 to 27F range and sends to other stations. 2) The L2/m station can receive data written to the devices in the range of B/W0 to 1FF and B/W280 to 37F by other station.
Page 91 SPECIFICATIONS Local station No. 2 ( 2) in third tier-1 1) The 2 station writes data to the devices in the range of B/W1C0 to 1FF and sends it to the other stations. 2) The 2 station can receive data written to the devices in the range of B/W0 to 1BF by other stations.
Page 92: Transient Transmission Function
MELSECNET mode MELSECNET MELSECNET/B MELSECNET MELSECNET MELSECNET MELSECNET MELSECNET MELSECNET Operating Mode mode composite mode mode mode composite mode mode SPECIFICATIONS Applicability 5.3.2 Transient transmission function The transient transmission is a function to: • Read/write from/to devices (T, C, D, and W) in a local station from the master station; •...
Page 93 SPECIFICATIONS Read/write of buffer memory in a special function module installed to a remote I/O station Use RFRP or RTOP instruction to read/write buffer memory of a special function module installed to a remote I/O station from the master station. Data communication can be executed between the master station and a remote I/O station only when RFRP or RTOP instruction is executed.
Page 94 SPECIFICATIONS Accessing other station with a peripheral device connected to programmable controller CPU When accessing to other station from the peripheral device, the station which can be accessed depends on types of access source station (master station, local station, or remote I/O station).
Page 95: Automatic Return Function
MELSECNET mode MELSECNET MELSECNET/B MELSECNET MELSECNET MELSECNET MELSECNET MELSECNET MELSECNET Operating Mode mode composite mode mode mode composite mode mode SPECIFICATIONS Applicability 5.3.3 Automatic return function Automatic return function If an error occurs to a local station or a remote I/O station, it is disconnected from the data link system to maintain the data link with the normally operating stations.
Page 96: Loopback Function
MELSECNET mode MELSECNET MELSECNET/B MELSECNET MELSECNET MELSECNET MELSECNET MELSECNET MELSECNET Operating Mode mode composite mode mode mode composite mode mode SPECIFICATIONS Applicability 5.3.4 Loopback function Loopback function The MELSECNET data link system has a double configuration of link cables (optical fiber or coaxial).
Page 97 SPECIFICATIONS Data link when the forward loop is faulty If data link using the forward loop is disabled due to a broken cable or a problem with a forward loop cable connector, the loop is automatically switched from "forward" to "reverse"...
Page 98 SPECIFICATIONS Data link when both the forward and reverse loops are faulty When a fault occurs to the cables of forward and reverse loops and the cable connecting connector, the link loops back toward the master station in front of faulty station, and data link is maintained by the normally operating.
Page 99 SPECIFICATIONS Data link when a power failure occurs to local station or remote I/O station If the data link is disabled due to power failure at a local station or a remote I/O station, the link loops back toward the master station, and the data link is maintained by the normally operating stations.
Page 100: Fault Detection Function
MELSECNET mode MELSECNET MELSECNET/B MELSECNET MELSECNET MELSECNET MELSECNET MELSECNET MELSECNET Operating Mode mode composite mode mode mode composite mode mode SPECIFICATIONS Applicability 5.3.5 Fault detection function In the data link system, the data link operation status is stored in the special relays (M) and special registers (D) so that it can be easily checked with a sequence program and peripheral device.
Page 101 SPECIFICATIONS Events checked by local stations (a) Data communication status with the master station • Checks if cyclic communication is executed normally.(M9246) • Checks if cyclic communication is executed normally from the master station for the second tier when the host station is a local station for the third tier. (M9247) •...
Page 102 SPECIFICATIONS When MELSECNET/B data link system is used Events checked by the master station (a) Data communication status with a slave station (local station and remote I/O station) • Stores stations in which a communication error occurs. (D9228, D9229) • Stores stations at which initial communication, necessary for starting communication, has not been completed.
Page 103 SPECIFICATIONS Events checked by a local station (a) Data communications status with the master station • Checks if cyclic data communications is normally executed. (M9246) • Checks if cyclic communication is executed normally from the master station for the second tier when the host station is a local station for the third tier. (M9247) •...
Page 104: Self-Diagnostics Function
MELSECNET mode MELSECNET MELSECNET/B MELSECNET MELSECNET MELSECNET MELSECNET MELSECNET MELSECNET Operating Mode mode composite mode mode mode composite mode mode SPECIFICATIONS Applicability 5.3.6 Self-diagnostics function The self-diagnostics function is a function to check the link module hardware and detect errors like breaking of the cables for data link. The self-diagnostics function includes the following three tests.
Page 105: Extensive Use Of Link Relays (B) And Link Registers (W) In A Three-Tier System
MELSECNET mode MELSECNET MELSECNET/B MELSECNET MELSECNET MELSECNET MELSECNET MELSECNET MELSECNET Operating Mode mode composite mode mode mode composite mode mode SPECIFICATIONS Applicability 5.3.7 Extensive use of link relays (B) and link registers (W) in a three-tier system Number of link relay (B) and link register (W) points that can be used in a system is as follows: MELSECNET mode ......
Page 106 SPECIFICATIONS Expanded link relay (B) and link register (W) range The device range that is not assigned to the link parameters for the second tier can be assigned to the link parameters for the third tier (third tier-1, third tier-2, ... third tier-n).
Page 107 SPECIFICATIONS Data communication range with expanded link relays (B) and link registers (W) (a) Link relays (B) and link registers (W) used by the two-tier link cannot be used for sending data to the local stations connected to any of the third-tier links. They can be used to send data to the master stations (L1/m, L2/m, .., Ln/m) for the third tiers.
Page 108: Melsecnet Mode And Melsecnet Composite Mode
MELSECNET mode MELSECNET MELSECNET/B MELSECNET MELSECNET MELSECNET MELSECNET MELSECNET MELSECNET Operating Mode mode composite mode mode mode composite mode mode SPECIFICATIONS Applicability 5.3.8 MELSECNET mode and MELSECNET composite mode When a MELSECNET mode-compatible link module is used as the master station, the operation mode for the MELSECNET data link system can be selected in the MELSECNET mode or the MELSECNET...
Page 109 SPECIFICATIONS Fig 5.9 System using MELSECNET mode 5 - 31...
Page 110 SPECIFICATIONS MELSECNET composite mode In the MELSECNET composite mode, MELSECNET mode-compatible local stations and remote I/O stations can be connected to the master station (MELSECNET mode-compatible data link module). By selecting the MELSECNET composite mode, data link modules used in the MELSECNET mode (previous MELSECNET data link system) and those compatible with the MELSECNET mode can be used within the same data link.
Page 111 SPECIFICATIONS Fig 5.10 System using MELSECNET composite mode REMARK (1) When a MELSECNET mode-compatible link module is used for the master station, the system operates in the MELSECNET mode even if a MELSECNET mode-compatible link module is connected to a local station.
Page 112: Optical Fiber Cable Specifications
Special skills and tools are required for connecting optical fiber cables to connectors. In addition, dedicated connector plugs are also needed. When purchasing any of the connector plugs, please consult your local Mitsubishi system service representative. 5.4.1 SI/GI-type optical fiber cable The Table 5.5 shows specifications of SI/GI-type optical fiber cable.
Page 113: Coaxial Cable Specifications
3.8mm (0.15inch) (Single annealed copper wire mesh) diameter (Single annealed copper wire mesh) Connector plug for 5C-2V Applicable Connector plug for 3C-2V (BNC-P-5 or BNC-P-5DV-SA(01) connector plug (BNC-P-3-Ni is recommended.) is recommended.) REMARK Consult nearest Mitsubishi representative with connector plug. 5 - 35...
Page 114: Connector For The Coaxial Cable
MELSECNET mode MELSECNET MELSECNET/B MELSECNET MELSECNET MELSECNET MELSECNET MELSECNET MELSECNET Operating Mode mode composite mode mode mode composite mode mode SPECIFICATIONS Applicability 5.5.2 Connector for the coaxial cable The following explains the structure and connecting procedures of the BNC connector (connector plug for the coaxial cable).
Page 115 SPECIFICATIONS POINT (1) Use caution as follows when soldering the contact to the internal conductor. (a) Solder must not be pumped up at soldering part. (b) The tail end of the contact and the cut end of the insulator must contact close to each other.
Page 116: Twisted Pair Cable Specifications
SPECIFICATIONS Twisted Pair Cable Specifications This section explains the twisted pair cable for the MELSECNET/B data link system. Table 5.7 Shielded twisted pair cable Model name KNPEV-SB 0.5SQ Cable type Shielded twisted pair cable Number of cores Conductive resistance (20 39.4 /km or lower Insulation resistance (20...
Page 117 SPECIFICATIONS MEMO 5 - 39...
Page 118: Link Data Send/Receive Processing And Processing Time
MELSECNET mode MELSECNET MELSECNET/B MELSECNET MELSECNET MELSECNET MELSECNET MELSECNET MELSECNET Operating Mode LlNK DATA SEND/RECEIVE PROCESSING mode composite mode mode mode composite mode mode AND PROCESSING TlME Applicability LINK DATA SEND/RECEIVE PROCESSING AND PROCESSING TIME This chapter describes how link data are sent or received in the data link system and it's processing time.
Page 119: Link Refresh Execution Timing
MELSECNET mode MELSECNET MELSECNET/B MELSECNET MELSECNET MELSECNET MELSECNET MELSECNET MELSECNET Operating Mode LlNK DATA SEND/RECEIVE PROCESSING mode composite mode mode mode composite mode mode AND PROCESSING TlME Applicability 6.1.2 Link refresh execution timing The link refresh executing timing can be divided into the following three types. Immediately after the completion of a link scan A link refresh will be executed when a link scan is completed.
Page 120 LlNK DATA SEND/RECEIVE PROCESSING AND PROCESSING TlME POINT (1) *1....The link refresh will be executed only after the execution of an END instruction in a sequence program when the programs steps between step 0 and the END instruction are set by the sequence program as a link-refresh inhibited zone.
Page 121: Link Data During A Communication Error
MELSECNET mode MELSECNET MELSECNET/B MELSECNET MELSECNET MELSECNET MELSECNET MELSECNET MELSECNET Operating Mode LlNK DATA SEND/RECEIVE PROCESSING mode composite mode mode mode composite mode mode AND PROCESSING TlME Applicability 6.1.3 Link data during a communication error The following describes how the link data used for data link is processed when a communication error occurs.
Page 122 LlNK DATA SEND/RECEIVE PROCESSING AND PROCESSING TlME (c) Normally operating local stations can recognize the station number at which the communication error has occurred by reading the data in M9255 and D9252 to D9255. At the link devices which receive data from the station at which the communication error has occurred, the data is maintained in a state just before the occurrence of communication error.
Page 123: Transmission Delay Time In Two-Tier System
LlNK DATA SEND/RECEIVE PROCESSING AND PROCESSING TlME Transmission Delay Time in Two-Tier System Calculate the transmission delay time in MELSECNET and MELSECNET/B data link system using the following times for the formulas given in Section 6.3. • Link refresh time for the master, local, and remote I/O stations •...
Page 124: Transmission Delay Time In A Two-Tier System
MELSECNET mode MELSECNET MELSECNET/B MELSECNET MELSECNET MELSECNET MELSECNET MELSECNET MELSECNET Operating Mode LlNK DATA SEND/RECEIVE PROCESSING mode composite mode mode composite mode mode mode AND PROCESSING TlME Applicability 6.2.1 Transmission delay time in a two-tier system This section shows the maximum transmission delay times of a data link in a link data system.
Page 125 LlNK DATA SEND/RECEIVE PROCESSING AND PROCESSING TlME M < L < LS , L < M < LS M < LS < L 6 - 8...
Page 126 MELSECNET mode MELSECNET MELSECNET/B MELSECNET MELSECNET MELSECNET MELSECNET MELSECNET MELSECNET Operating Mode LlNK DATA SEND/RECEIVE PROCESSING mode composite mode mode composite mode mode mode AND PROCESSING TlME Applicability The following shows the transmission delay times when the CPU of the type that makes a link refresh after END processing is used.
Page 127 LlNK DATA SEND/RECEIVE PROCESSING AND PROCESSING TlME M < L < LS, L < M < LS M < LS < L 6 - 10...
Page 128: Link Refresh Time
MELSECNET mode MELSECNET MELSECNET/B MELSECNET MELSECNET MELSECNET MELSECNET MELSECNET MELSECNET Operating Mode LlNK DATA SEND/RECEIVE PROCESSING mode composite mode mode mode composite mode mode AND PROCESSING TlME Applicability 6.2.2 Link refresh time The following describes the method used for calculating the link refresh processing time. The symbols used for calculating the link refresh processing time are listed below: B :Total number of link relays (B) used in all stations W :Total number of link registers (W) used in all stations...
Page 129 LlNK DATA SEND/RECEIVE PROCESSING AND PROCESSING TlME Model A0J2HCPUP21/R21 1.59 5.02 AnNCPUP21/R21 A2ACPUP21(S1)/R21 0.26 0.18 1.45 A3ACPUP21/R21 0.20 0.14 1.09 AnNCPUP21/R21 + AJ71AP21(S3)/R21 A2ACPU(S1) + AJ71AP21(S3)/R21 0.54 0.54 4.32 A3ACPU + AJ71AP21(S3)/R21 0.48 0.52 4.16 A2UCPU(S1) + AJ71AP21(S3)/R21 0.54 0.54 4.32 A3UCPU + AJ71AP21(S3)/R21 0.48...
Page 130 LlNK DATA SEND/RECEIVE PROCESSING AND PROCESSING TlME Local stations Use the following formula to calculate the link refresh time required for a local station. When the link operates in the MELSECNET mode or the MELSECNET composite mode, the number of B/W points is all points set with the first half and second half link parameters.
Page 131 LlNK DATA SEND/RECEIVE PROCESSING AND PROCESSING TlME When a MELSECNET/B data link system is used Master station Use the following formula to calculate the link refresh time required for a master station. When the link operates in the MELSECNET mode or the MELSECNET composite mode, the number of B/W points is all of the points set with the first half and second half link parameters.
Page 132 LlNK DATA SEND/RECEIVE PROCESSING AND PROCESSING TlME Local stations Use the following formula to calculate the link refresh time required for a local station. When the link operates in the MELSECNET mode or the MELSECNET composite mode, the number of B/W points is all points set with the first half and second half link parameters.
Page 133: Link Data Communication Time (Link Scan)
MELSECNET mode MELSECNET MELSECNET/B MELSECNET MELSECNET MELSECNET MELSECNET MELSECNET MELSECNET Operating Mode LlNK DATA SEND/RECEIVE PROCESSING mode composite mode mode mode composite mode mode AND PROCESSING TlME Applicability 6.2.3 Link data communication time (link scan) The following describes the method used for calculating the link data communication time. When a MELSECNET data link system is used In the MELSECNET mode In the MELSECNET...
Page 134 MELSECNET mode MELSECNET MELSECNET/B MELSECNET MELSECNET MELSECNET MELSECNET MELSECNET MELSECNET Operating Mode LlNK DATA SEND/RECEIVE PROCESSING mode composite mode mode mode composite mode mode AND PROCESSING TlME Applicability When a MELSECNET/B data link system is used In the MELSECNET mode In the MELSECNET mode In the MELSECNET...
Page 135 LlNK DATA SEND/RECEIVE PROCESSING AND PROCESSING TlME 1) K in the case of 125kbps 2) K in the case of 250kbps (ms) (a) When the first and latter halves of link parameters are set (b) When only the first half of link parameters is set (ms) 9 10 (Kbyte)
Page 136: Transmission Delay Time In Three-Tier System
MELSECNET mode MELSECNET MELSECNET/B MELSECNET MELSECNET MELSECNET MELSECNET MELSECNET MELSECNET Operating Mode LlNK DATA SEND/RECEIVE PROCESSING mode composite mode mode mode composite mode mode AND PROCESSING TlME Applicability Transmission Delay Time in Three-Tier System Calculate the transmission delay time for a three-tier system by adding the following delay factors to the transmission delay time.
Page 137 LlNK DATA SEND/RECEIVE PROCESSING AND PROCESSING TlME Examples: To transmit B/W data from M to 1 (a) If (L1/m scan time) > (third tier-1 link scan time) (Transmission delay time from M to L1/m) + (Transmission delay time from L1/m to 1) + (L1/m scan time) (b) If (L1/m scan time) <...
Page 138: Time To Access Another Station From A Peripheral Device
LlNK DATA SEND/RECEIVE PROCESSING AND PROCESSING TlME Time to Access Another Station from a Peripheral Device This section describes the processing time when accessing to other station from a peripheral device. (For the processing time of LRDP/LWTP and RFRP/RTOP, refer to Section 6.2.3.) When a MELSECNET/B data link system is used, the transmission processing time varies depending on the set communication speed and the total number of stations.
Page 139: Data Link Settings
MELSECNET mode MELSECNET MELSECNET/B MELSECNET MELSECNET MELSECNET MELSECNET MELSECNET MELSECNET Operating Mode mode composite mode mode mode composite mode mode DATA LINK SETTINGS Applicability DATA LINK SETTINGS This chapter describes the setting of the number of modules and the setting of the network refresh parameters and link parameters, which are required for communications with other stations in the data link system.
Page 140: Setting Of The Number Of Modules
MELSECNET mode MELSECNET MELSECNET/B MELSECNET MELSECNET MELSECNET MELSECNET MELSECNET MELSECNET Operating Mode mode composite mode mode mode composite mode mode DATA LINK SETTINGS Applicability Setting of the Number of Modules Set the number of the data link modules installed to the AnUCPU, QnACPU, A2ASCPU(S1), A2USHCPU-S1 or Q2AS(H)CPU(S1) and head I/O numbers etc.
Page 141 DATA LINK SETTINGS Setting example An example of setting the number of modules is shown below. (a) System configuration example Fig 7.1 System configuration example (b) Setting screen Fig 7.2 shows the setting screen for the above system configuration example. Fig 7.2 Screen for setting the number of modules 7 - 3...
Page 142: Network Refresh Parameters
MELSECNET mode MELSECNET MELSECNET/B MELSECNET MELSECNET MELSECNET MELSECNET MELSECNET MELSECNET Operating Mode mode composite mode mode mode composite mode mode DATA LINK SETTINGS Applicability Network Refresh Parameters The network refresh parameters are set to transfer the link device (LB, LW, LX, LY) which are stored in the data link module to the devices that can be used in a sequence program.
Page 143 DATA LINK SETTINGS Default values The default values of the network refresh parameters are assigned according to the setting of the number of modules. No settings are required unless specific changes must be made to the default values. Table 7.1 shows the default values. The module Nos. correspond to the numbers in the setting of the number of modules.
Page 144 DATA LINK SETTINGS When a MELSECNET data link module is mounted, the default values of the network refresh parameters are assigned as follows: 1) Always assigned to the area of module No. 1. 2) If two MELSECNET data link modules are mounted, they are assigned to the area for one module.
Page 145 DATA LINK SETTINGS Setting items The setting items of the network refresh parameters include the refresh ranges of LB, LW, LX, LY, SB and SW and the setting of the error history area. The following describes each setting item. Table 7.2 shows the network refresh parameter setting items of the MELSECNET . Table 7.2 Network refresh parameter setting items MELSECNET/10 MELSECNET...
Page 146 DATA LINK SETTINGS (b) Refresh range setting for LW 1) The refresh destinations of LW are the link register (W). 2) The transfer size is in units of 1 point. (c) Refresh range setting for LX/LY 1) The refresh destination of LX is the input (X), and that of LY is the output (Y) The actual I/O and later can be set as the refresh destination.
Page 147 DATA LINK SETTINGS Setting example In the system configuration exemplified in Fig 7.4, an example of setting the network refresh parameters to assign the refresh ranges in Table 7.3 is shown below. Fig 7.4 System configuration example Table 7.3 Refresh ranges MELSECNET master Module type Module No.
Page 148 DATA LINK SETTINGS (a) Setting screens Setting of network module No. 1 7 - 10...
Page 149: Link Parameters
MELSECNET mode MELSECNET MELSECNET/B MELSECNET MELSECNET MELSECNET MELSECNET MELSECNET MELSECNET Operating Mode mode composite mode mode mode composite mode mode DATA LINK SETTINGS Applicability Link Parameters 7.4.1 Link parameters to be set for the MELSECNET mode When the MELSECNET mode is used, only one type of link parameter is used. On the link parameter setting screen, set the data for the following items.
Page 150: Link Parameters To Be Set For The Melsecnet
MELSECNET mode MELSECNET MELSECNET/B MELSECNET MELSECNET MELSECNET MELSECNET MELSECNET MELSECNET Operating Mode mode composite mode mode composite mode mode mode DATA LINK SETTINGS Applicability 7.4.2 Link parameters to be set for the MELSECNET mode When the MELSECNET mode is used, two types of link parameter (first half and second half) are provided.
Page 151 DATA LINK SETTINGS Link parameter setting screens The following shows the link parameter setting screens. (a) First half link parameters (b) Second half link parameters 7 - 13...
Page 152: Link Parameters To Be Set For The Melsecnet Composite Mode
MELSECNET mode MELSECNET MELSECNET/B MELSECNET MELSECNET MELSECNET MELSECNET MELSECNET MELSECNET Operating Mode mode composite mode mode composite mode mode mode DATA LINK SETTINGS Applicability 7.4.3 Link parameters to be set for the MELSECNET composite mode When the MELSECNET composite mode is used, two types of link parameters (first half and second half) are provided.
Page 153 DATA LINK SETTINGS Local station assignment Assign the device range to be used by the local station for writing data to the link relays (B) and link registers (W). REMARK The device range that can be assigned to the second half link parameters is the range assigned to the first half link parameters: "(final device number) + 1".
Page 154 DATA LINK SETTINGS Link parameter setting screen The following shows link parameter setting screens. (a) First half link parameters (b) Second half link parameters 7 - 16...
Page 155: Monitoring Time Setting
MELSECNET mode MELSECNET MELSECNET/B MELSECNET MELSECNET MELSECNET MELSECNET MELSECNET MELSECNET Operating Mode mode composite mode mode mode composite mode mode DATA LINK SETTINGS Applicability Monitoring Time Setting The monitoring time is the reference time used by the system to determine whether communication between the master station and all slave stations (local stations and remote I/O stations) is being executed normally.
Page 156 DATA LINK SETTINGS Setting the monitoring time The monitoring time can be set between 10 to 2000ms in units of 10ms. (The usual setting is 2000ms.) Setting the minimum value to monitoring time is valid for the case to immediately turn off the output of remote I/O stations where communication error occurred.
Page 157: Common Element
MELSECNET mode MELSECNET MELSECNET/B MELSECNET MELSECNET MELSECNET MELSECNET MELSECNET MELSECNET Operating Mode mode composite mode mode mode composite mode mode DATA LINK SETTINGS Applicability Common Element The following describes the common information to know before assigning link parameters. 7.6.1 Maximum number of link points per station The maximum number of link points (number of points assigned to a station by link parameters) of "B, W, X, Y"...
Page 158: Determining The Link Relay (B) Assignment Range
MELSECNET mode MELSECNET MELSECNET/B MELSECNET MELSECNET MELSECNET MELSECNET MELSECNET MELSECNET Operating Mode mode composite mode mode mode composite mode mode DATA LINK SETTINGS Applicability Maximum number of link points per remote I/O station The maximum number of link points which can be assigned to a remote I/O station is 512 I/O points (X/Y0 to 1FF) or less, and the total link data size must be set to 512 bytes.
Page 159: Determining The Link Register (W) Assignment Range
MELSECNET mode MELSECNET MELSECNET/B MELSECNET MELSECNET MELSECNET MELSECNET MELSECNET MELSECNET Operating Mode mode composite mode mode mode composite mode mode DATA LINK SETTINGS Applicability 7.6.3 Determining the link register (W) assignment range Link registers (W) are used for communications between the master station and a local station and between the master station and a remote I/O station.
Page 160 DATA LINK SETTINGS 2) The system uses the M R area to execute RFRP/RTOP instructions. Consider the range used by the system when assigning the M R area. [Number of points used by the system] The link register (W) 1 point is used for one special function module installed to a remote I/O station.
Page 161: Determining The Input (X) And Output (Y) Assignment Range
MELSECNET mode MELSECNET MELSECNET/B MELSECNET MELSECNET MELSECNET MELSECNET MELSECNET MELSECNET Operating Mode mode composite mode mode mode composite mode mode DATA LINK SETTINGS Applicability 7.6.4 Determining the input (X) and output (Y) assignment range Assignment of input (X) and output (Y) can be executed to the link parameter of MELSECNET mode and the first half link parameters of MELSECNET composite mode.
Page 162: Link Parameters In The Melsecnet Mode
MELSECNET mode MELSECNET MELSECNET/B MELSECNET MELSECNET MELSECNET MELSECNET MELSECNET MELSECNET Operating Mode mode composite mode mode mode composite mode mode DATA LINK SETTINGS Applicability Link Parameters in the MELSECNET Mode The following describes the link parameter setting when the MELSECNET mode is used. (When the MELSECNET composite mode is used, the first half link parameters can be set in a similar way.) The system configuration in the MELSECNET mode includes the following three types.
Page 163 DATA LINK SETTINGS Link parameter setting example Fig 7.8 shows a link parameter setting of a local system when the MELSECNET mode is used. Fig 7.8 System configuration example 7 - 25...
Page 164 DATA LINK SETTINGS Assignment of link relay (B) (a) Fig 7.9 shows the case when assigning 256 points to the master station, 128 points to local station No.1, 128 points to local station No.2, and 128 points empty area between local station No.1 and local station No.2. Fig 7.9 Link relay (B) assignment example (b) The empty area marked with *1 in the M/L area in Fig 7.9 cannot be used as a substitute for internal relay (M) in the master station and all local stations.
Page 165 DATA LINK SETTINGS Assignment of link register (W) (a) Assignment for the master station and local stations (M/L area) Fig 7.10 shows the case when assigning 256 points to the master station, 128 points to local station No.1, 196 points to local station No.2, and 128 points empty area between local station No.1 and local station No.2.
Page 166 DATA LINK SETTINGS Assignment of inputs (X) and outputs (Y) (a) The range used for data link by the master station The master station uses the X/Y0 to X/Y14F range as inputs and outputs of host station. The X/Y150 to X/Y7FF range can be used for the data link. (b) Assignment for local stations In this example, inputs (X) and outputs (Y) are not required because there is an empty area in the link relay (B) assignment.
Page 167 DATA LINK SETTINGS Link parameter setting When the assignment of (1) to (3) is executed, set the link parameters as shown below. 7 - 29...
Page 168: Remote I/O System Assignment And Link Parameter Setting Example
MELSECNET mode MELSECNET MELSECNET/B MELSECNET MELSECNET MELSECNET MELSECNET MELSECNET MELSECNET Operating Mode mode composite mode mode mode composite mode mode DATA LINK SETTINGS Applicability 7.7.2 Remote I/O system assignment and link parameter setting example The following describes the assignment of link relays, link registers, inputs, and outputs and link parameters used for the remote I/O system.
Page 169 DATA LINK SETTINGS Link parameter setting example Fig 7.12 shows a link parameter setting of a remote I/O system when the MELSECNET mode is used. Fig 7.12 System configuration example 7 - 31...
Page 170 DATA LINK SETTINGS Assignment of link relay (B) Data link cannot be executed by using a link relay in a remote I/O system. (Setting at link parameter is unnecessary.) Assignment of link register (W) (a) Assignment for remote I/O stations (M R area, M R area) 1) Assign 16 points for the RTOP instruction and 16 points for the RFRP...
Page 171 DATA LINK SETTINGS Assignment of inputs (X) and outputs (Y) (a) Input and output range used for data link by master station The master station uses the X/Y0 to X/Y14F range as I/O of host station. The X/ Y150 to 7FF range can be used for the data link. (b) Assignment of remote I/O stations 1) Assignment of remote I/O station No.1 Inputs (X)
Page 172 DATA LINK SETTINGS Link parameter setting When the assignment of (1) to (3) is executed, set the link parameters as shown in the figure below. 7 - 34...
Page 173: Local/Remote I/O System Assignment And Link Parameter Setting Example
MELSECNET mode MELSECNET MELSECNET/B MELSECNET MELSECNET MELSECNET MELSECNET MELSECNET MELSECNET Operating Mode mode composite mode mode mode composite mode mode DATA LINK SETTINGS Applicability 7.7.3 Local/remote I/O system assignment and link parameter setting example The following describes the assignment of link relays, link registers, inputs, and outputs and the link parameters.
Page 174 DATA LINK SETTINGS Assign the input (X) and output (Y) range used for data link to the I/O number used in the I/O module and special function module by the master station I/O. (Refer to Section 7.6.4) (a) Divide the area used for data link into an M/R area (for communication between the master station and a remote I/O station) and an M/L area (for communication between the master station and a local station) to assign the range.
Page 175 MELSECNET mode MELSECNET MELSECNET/B MELSECNET MELSECNET MELSECNET MELSECNET MELSECNET MELSECNET Operating Mode mode composite mode mode mode composite mode mode DATA LINK SETTINGS Applicability Link parameter setting example The following explains the procedure for setting link parameters when a local/remote I/O system is used in the MELSECNET mode.
Page 176 DATA LINK SETTINGS Assignment of link relays (B) (a) Fig 7.17 shows the case when assigning 256 points to the master station, 128 points to local station No.2, 128 points to local station No.3, and 128 points empty area between local station No.2 and local station No.3. Fig 7.17 Link relay (B) assignment example (b) The empty area marked with *1 in the M/L area in Fig 7.17 cannot be used as a substitute for internal relays (M) in the master station and all local stations.
Page 177 DATA LINK SETTINGS Assignment of link registers (W) (a) Assignment for the master station and local stations (M/L area) 256 points to the master station, 128 points to local station No.2, and 196 points to local station No.3 are assigned (b) Assignment for the remote I/O stations (M R area, M R area)
Page 178 DATA LINK SETTINGS Assignment of inputs (X) and outputs (Y) (a) Input and output range used for data link by the master station The master station uses the X/Y0 to X/Y14F range as I/O of host station. For the data link, the X/Y150 to X/Y7FF range can be used. (b) Assignment of remote I/O stations 1) Assignment of remote I/O station No.1 Inputs (X):...
Page 179 DATA LINK SETTINGS Link parameter setting example When the assignment of (1) to (3) is executed, set the link parameters as shown in the figure below. 7 - 41...
Page 180: Link Parameters In The Melsecnet
MELSECNET mode MELSECNET MELSECNET/B MELSECNET MELSECNET MELSECNET MELSECNET MELSECNET MELSECNET Operating Mode mode composite mode mode composite mode mode mode DATA LINK SETTINGS Applicability Link Parameters in the MELSECNET Mode The following describes link parameter setting when the MELSECNET mode is used. When setting the link parameters, consider the following points for assignment.
Page 181 DATA LINK SETTINGS Link parameter setting example The link parameter setting of the system configuration shown in Fig 7.20 is explained when the MELSECNET mode is used. Fig 7.20 Local system configuration example Number of assigned points (a) Link relays (B) 512 points and link registers (W) 512 points for the master station (b) Link relays (B) 256 points and link registers (W) 256 points for the local station No.1 (c) Link relays (B) 512 points and link registers (W) 256 points for the local station...
Page 182 DATA LINK SETTINGS Assignment of link relays (B) Fig 7.21 Link relay (B) assignment example (a) The empty area marked with *1 in the M/L area for the first half link parameters in Fig 7.21 assigned cannot be used as a substitute for internal relays (M) in the master station and all local stations.
Page 183 DATA LINK SETTINGS Assignment of link registers (W) Fig 7.22 Link register (W) assignment example (a) The empty area marked with *1 in the M/L area for the first half link parameters in Fig 7.22 cannot be used as a substitute for data registers (D) in the master station and all local stations.
Page 184 DATA LINK SETTINGS Assignment of inputs (X) and outputs (Y) In this system example, inputs (X) and outputs (Y) are not to be used because there is an empty area in the link relay (B) assignment. However, to simplify the explanation, 128 input (X) points and 128 output (Y) points each are assigned to local stations No.1 and No.3.
Page 185 DATA LINK SETTINGS Link parameter setting Set the link parameters assigned as (1) to (5) as follows: (a) First half link parameters (b) Second half link parameters 7 - 47...
Page 186: Link Parameters In The Melsecnet Composite Mode
MELSECNET mode MELSECNET MELSECNET/B MELSECNET MELSECNET MELSECNET MELSECNET MELSECNET MELSECNET Operating Mode mode composite mode mode composite mode mode mode DATA LINK SETTINGS Applicability Link Parameters in the MELSECNET Composite Mode The following describes the link parameter setting when the MELSECNET composite mode is used.
Page 187 DATA LINK SETTINGS Make sure that the number of link points per station is as follows. (Refer to Section 7.6.1.) • Master station first half link parameters....1024 bytes or less • Master station second half link parameters..1024 bytes or less •...
Page 188: Remote I/O System Assignment
MELSECNET mode MELSECNET MELSECNET/B MELSECNET MELSECNET MELSECNET MELSECNET MELSECNET MELSECNET Operating Mode mode composite mode mode composite mode mode mode DATA LINK SETTINGS Applicability 7.9.2 Remote I/O system assignment When setting link parameters of a remote I/O system, consider the following points for assignment.
Page 189 DATA LINK SETTINGS 2) Range used by the system The range used by the system is from the head device number of M area assigned from each remote I/O station to "number of use points - 1 ". For example, when three special function modules are installed to remote I/O station No.2, the range W360 to 362 in the M R area W360 to W3AF shown below is used by the system.
Page 190: Local/Remote I/O System Assignment
MELSECNET mode MELSECNET MELSECNET/B MELSECNET MELSECNET MELSECNET MELSECNET MELSECNET MELSECNET Operating Mode mode composite mode mode composite mode mode mode DATA LINK SETTINGS Applicability 7.9.3 Local/remote I/O system assignment When setting link parameters of a local/remote I/O system, consider the following points for assignment.
Page 191 DATA LINK SETTINGS (c) The device range that can be assigned with the second half link parameters is the range assigned with the first half link parameters: "(final device) + 1 " or later. (Example: If the range of B0 to FF is assigned to the first link parameters, "B100" or later can be assigned to the second half parameters) If 0 point is assigned with the first half link parameters, assignment with the second half link parameters can be started with W0.
Page 192 DATA LINK SETTINGS (b) Consider the range used by the system when assigning the M R area. The system uses the M R area to execute the RFRP/RTOP instructions. 1) Number of points used by the system The link register (W) 1 point is used for one special function module installed to a remote I/O station.
Page 193 DATA LINK SETTINGS POINT (1) If the M R area used by the system is used incorrectly in a user program, data cannot be read/written correctly, when the RFRP/RTOP instruction is executed. (2) The number of link points can be reduced by mounting modules to a remote I/O station in groups of input modules, special function modules, and output modules as shown below.
Page 194 MELSECNET mode MELSECNET MELSECNET/B MELSECNET MELSECNET MELSECNET MELSECNET MELSECNET MELSECNET Operating Mode mode composite mode mode composite mode mode mode DATA LINK SETTINGS Applicability 7.9.4 Link parameter setting example The following describes the link parameter setting system configuration shown in Fig 7.26, using the MELSECNET composite mode.
Page 195 DATA LINK SETTINGS Assignment of link relays (B) (a) Assign 256 points for the master station, 256 points for local station No.2, and 256 points for local station No.3 with the first half link parameters. Assign 256 points for the master station and 256 points for the local station No.3 with the second half link parameters.
Page 196 DATA LINK SETTINGS Assignment of link registers (W) (a) Assignment for the master station and local stations (M/L area) Assign 256 points for the master station (M), 256 points for local station No.2 (L2), and 128 points for local station No.3 (L3) with the first half link parameters. Assign 256 points for the master station (M) and 256 points for local station No.3 (L3) with the second half link parameters.
Page 197 DATA LINK SETTINGS Assignment of inputs (X) and outputs (Y) (a) Input and output range can be used for data link by master station The master station uses the X/Y0 to X/Y14F range as I/O of host station. For the data link, the X/Y150 to X/Y7FF range can be used.
Page 198: Link Parameter Setting Example
DATA LINK SETTINGS Link parameter setting When the assignment of (1) to (4) is executed, set the link parameters as shown in the figure below. (a) First half link parameters (b) Second half link parameters 7 - 60...
Page 199: Three-Tier System Assignment
MELSECNET mode MELSECNET MELSECNET/B MELSECNET MELSECNET MELSECNET MELSECNET MELSECNET MELSECNET Operating Mode mode composite mode mode mode composite mode mode DATA LINK SETTINGS Applicability 7.10 Three-Tier System Assignment The following describes the link parameter setting required to use the three-tier system. The link parameter setting of the three-tier system is basically similar to that of the two-tier system described in Section 7.7 to 7.9.
Page 200 DATA LINK SETTINGS The input (X) and output (Y) range that can be assigned to the master station for the third tier can use the area starting from the I/O use range of host station. This is the same range as assignment range of the master station for the second tier. If inputs (X) and outputs (Y) are used to establish data link between the master station for the third tier and the master station for the second tier, the assignment range of the master station for the third tier should exclude this range.
Page 201 DATA LINK SETTINGS When the MELSECNET mode or MELSECNET composite mode is selected, the link relay (B) and link register (W) range that can be assigned with the first and second half link parameters is as shown below. (a) Assign the range assigned with the first half link parameters for the second tier with the first half link parameters for the third tier.
Page 202 DATA LINK SETTINGS In the three-tier system, link relays (B) and link registers (W) can be assigned to the ranges explained in (1) and (4). In the MELSECNET data link system, range check of link parameters for second tier and link parameters for third tier is performed. This check is called the consistency check.
Page 203 DATA LINK SETTINGS (b) The following consistency check is executed when there is difference between the number of link parameters set for the second tier and the number of link parameters set for the third tier. 1) When two types of link parameters are set for the second tier and one type of link parameters is set for the third tier: The consistency check is executed on the first half link parameters for the second tier and the first half link parameters for the third tier (including the...
Page 204: Using The Melsecnet Mode In The Second Tier
MELSECNET mode MELSECNET MELSECNET/B MELSECNET MELSECNET MELSECNET MELSECNET MELSECNET MELSECNET Operating Mode mode composite mode mode mode composite mode mode DATA LINK SETTINGS Applicability 7.10.2 Using the MELSECNET mode in the second tier The link relay (B) and link register (W) range which can be assigned to the third tier is described per operation mode used in the third tier.
Page 205 DATA LINK SETTINGS MELSECNET composite mode used in the third tier (a) First half link parameters for the third tier 1) The range assigned to the master station for the third tier with the link parameters for the second tier is used for the M/L area. 2) The M/R area in the second tier and the empty area in the W0 to 3FF range is used for the M/R area.
Page 206 MELSECNET mode MELSECNET MELSECNET/B MELSECNET MELSECNET MELSECNET MELSECNET MELSECNET MELSECNET Operating Mode mode composite mode mode composite mode mode mode DATA LINK SETTINGS Applicability 7.10.3 Using the MELSECNET mode in the second tier The link relay (B) and link register (W) range which can be assigned to the third tier is described per operation mode used in the third tier.
Page 207 DATA LINK SETTINGS MELSECNET composite mode used in the third tier (a) First half link parameters for the third tier 1) The range assigned to the master station for the third tier with the first half link parameters for the second tier is used for the M/L area. 2) The empty area within the W0 to 3FF range assigned with link parameters for the second tier is used for the M/R area.
Page 208: Using The Melsecnet Composite Mode In The Second Tier
MELSECNET mode MELSECNET MELSECNET/B MELSECNET MELSECNET MELSECNET MELSECNET MELSECNET MELSECNET Operating Mode mode composite mode mode composite mode mode mode DATA LINK SETTINGS Applicability 7.10.4 Using the MELSECNET composite mode in the second tier The link relay (B) and link register (W) range which can be assigned to the third tier is described per operation mode used in the third tier.
Page 209 DATA LINK SETTINGS MELSECNET composite mode used in the third tier (a) First half link parameters for the third tier 1) The range assigned to the master station for the third tier with the first half link parameters for the second tier is used for the M/L area. 2) The M/R area for the second tier and an empty area in the W0 to 3FF range is used for the M/R area.
Page 210: Link Parameter Setting Example
MELSECNET mode MELSECNET MELSECNET/B MELSECNET MELSECNET MELSECNET MELSECNET MELSECNET MELSECNET Operating Mode mode composite mode mode mode composite mode mode DATA LINK SETTINGS Applicability 7.10.5 Link parameter setting example The following describes the link parameters for the third tier, exemplifying the system configuration shown in Fig 7.44.
Page 211 DATA LINK SETTINGS Table 7.6 Number of assignment point for each station Second half link First half link parameter parameter L3/m Checking the operation mode to be used (a) Operation mode of the second tier: MELSECNET composite mode This is because the slave stations (local stations and remote I/O stations) are connected to either MELSECNET mode-compatible station or MELSECNET mode-compatible station.
Page 212 DATA LINK SETTINGS Assignment of link relays (B) Master ststion(M) Used as internal relays (M) Coil Contact in the master station Fig 7.45 Link relays (B) assignment example 7 - 74...
Page 213 DATA LINK SETTINGS Link using local station No. 3(L3/m) as the master station for the third tier Local station No. 2(L2) Master station (L3/m) Local station No. 1 ( 1) Local station No. 3 ( 3) Used as Used as Used as Used as internal...
Page 214 DATA LINK SETTINGS Assignment of link registers (W) Master station (M) Remote I/O station No. 1(R1) Fig 7.46 Link registers (W) assignment example (a) An empty area in the W0 to 5F range is used to assign an M/R area for the third tier with the link parameters for the second tier.
Page 215 DATA LINK SETTINGS Link using local station No. 3 (L3/m) as the master station for the third tier Local station Remote I/0 No. 2(L2) station No. 4 (R4) Remote I/O station Master station (L3/m) Local station No. 1 ( 1) Local station No.
Page 216 DATA LINK SETTINGS Inputs (X) and outputs (Y) (a) A memory map for the assignment example of inputs and outputs is shown in Fig 7.47. Fig 7.47 Inputs/outputs assignment example 7 - 78...
Page 217 DATA LINK SETTINGS Link parameter setting The following shows the link parameters assigned as (1) to (4). (a) First half link parameters for the second tier (b) Second half link parameters for the second tier 7 - 79...
Page 218 DATA LINK SETTINGS (c) First half link parameters for the third tier (d) Second half link parameters for the third tier 7 - 80...
Page 219: Assignment Of Inputs And Outputs To The Master Station In A Remote I/O System
MELSECNET mode MELSECNET MELSECNET/B MELSECNET MELSECNET MELSECNET MELSECNET MELSECNET MELSECNET Operating Mode mode composite mode mode composite mode mode mode DATA LINK SETTINGS Applicability 7.11 Assignment of Inputs and Outputs to the Master Station in a Remote I/O System When a remote I/O system is configured with the MELSECNET data link system, there are restrictions on the I/O assignment for the master station.
Page 220 DATA LINK SETTINGS As for I/O assignment of remote I/O station, a slot in which a module is installed cannot be assigned as an empty slot (S1: 0 point, S2: 16 points, S3: 32 points, S4: 48 points, S5: 64 points). If assigned to an empty slot, a "UNIT VERIFY ERROR" will occur.
Page 221: I/O Assignment Example
MELSECNET mode MELSECNET MELSECNET/B MELSECNET MELSECNET MELSECNET MELSECNET MELSECNET MELSECNET Operating Mode mode composite mode mode composite mode mode mode DATA LINK SETTINGS Applicability 7.11.2 I/O assignment example The following describes the I/O assignment of I/O number for a remote I/O station by GPP. The I/O assignment of remote I/O station is set on the "I/O LOCATING"...
Page 222 DATA LINK SETTINGS When the M/L area is assigned after the M/R area When the M/L area is assigned after the M/R area with the link parameters, the I/O assignment is as shown in the following example. (a) Link parameter assignment example Fig 7.50 shows the link parameter I/O assignment.
Page 223 DATA LINK SETTINGS When the M/R area is assigned after the M/L area When the M/R area is assigned after the M/L area with the link parameters, the I/O assignment is as shown in the following example. (a) Assignment example by link parameter Fig 7.51 shows the I/O assignment by link parameters.
Page 224: Procedures To Operation
MELSECNET mode MELSECNET MELSECNET/B MELSECNET MELSECNET MELSECNET MELSECNET MELSECNET MELSECNET Operating Mode mode composite mode mode mode composite mode mode PROCEDURES TO OPERATION Applicability PROCEDURES TO OPERATION This chapter describes procedures for data link and startup, station number setting, and precautions for wiring.
Page 225: Setting The Link Module Station Numbers
MELSECNET mode MELSECNET MELSECNET/B MELSECNET MELSECNET MELSECNET MELSECNET MELSECNET MELSECNET Operating Mode mode composite mode mode mode composite mode mode PROCEDURES TO OPERATION Applicability Setting the Link Module Station Numbers This section describes the station number setting for link modules and precautions for it. 8.2.1 Setting the link module station numbers in the MELSECNET data link system Assign station numbers from the master station (set "00"...
Page 226 PROCEDURES TO OPERATION Precautions for setting the link module station numbers The following shows the precautions for station number setting. Station numbers have to be consecutive. Station numbers cannot be skipped as Fig 8.2. If station numbers are not set consecutively, the time taken for the system to switch to the loopback mode when the slave station is powered off is increased.
Page 227 PROCEDURES TO OPERATION The station numbers in the same loop have to be all different. If the same station number is assigned to another station in the same loop, the link module closer to the receiving port of the master station is applied, and the link data in the other station is ignored.
Page 228: Setting The Link Module Station Numbers In The Melsecnet/B Data Link System
MELSECNET mode MELSECNET MELSECNET/B MELSECNET MELSECNET MELSECNET MELSECNET MELSECNET MELSECNET Operating Mode mode composite mode mode mode composite mode mode PROCEDURES TO OPERATION Applicability 8.2.2 Setting the link module station numbers in the MELSECNET/B data link system Assign station number from the master station (set "00" to the master station) in ascending order to the forward loop direction.
Page 229 PROCEDURES TO OPERATION Precautions for setting the link module station numbers The following shows the precautions for station number setting. Station numbers have to be consecutive. If station numbers are not set consecutively, the stations with incorrect station numbers are treated as communication faulty stations. The station numbers in the same loop have to be all different.
Page 230: Setting Communication Speed
PROCEDURES TO OPERATION Setting Communication Speed The overall distance of the MELSECNET/B data link system depends on the communication speed. Set the communication speed with the switch setting of link modules. (For the setting, refer to the manual for the link module.) The relationship between set communication speeds and overall distances is shown in Table 8.1.
Page 231: Optical Fiber Cable/Coaxial Cable Wiring
Table 8.2. For the connector A and allowable bend radius r of optical fiber cables, contact Mitsubishi Electric System & Service Co., Ltd. Table 8.2 Minimum allowable bend radius...
Page 232 PROCEDURES TO OPERATION (b) If cables are not connected between F-RD on the master station and F-SD on the final station, and between R-SD on the master station and R-RD on the final station, the data link is established in the loopback mode. Therefore, in case of an error, data link between the faulty station and the final station is disabled.
Page 233: Optical Fiber Cables Connections
MELSECNET mode MELSECNET MELSECNET/B MELSECNET MELSECNET MELSECNET MELSECNET MELSECNET MELSECNET Operating Mode mode composite mode mode mode composite mode mode PROCEDURES TO OPERATION Applicability 8.4.2 Optical fiber cables connections This section describes methods for connecting optical fiber cables with link modules. Connecting link modules with optical fiber cables Connect an optical fiber cable to a link module from the OUT connector to IN connector of the next station as shown in Fig 8.6 (Connect the cable from the OUT...
Page 234 PROCEDURES TO OPERATION Disconnecting optical fiber cables The following flowchart shows a method for disconnecting optical fiber cables. Disconnection Plug Turn OFF the power supply. Pull out a fixing part of a plug in the arrow direction. Cover the plug and jack with covers which covered them before connection and store them.
Page 235: Coaxial Cable Connections
MELSECNET mode MELSECNET MELSECNET/B MELSECNET MELSECNET MELSECNET MELSECNET MELSECNET MELSECNET Operating Mode mode composite mode mode mode composite mode mode PROCEDURES TO OPERATION Applicability 8.4.3 Coaxial cable connections This section describes methods for connecting coaxial cables with link modules. Connecting link modules with coaxial cables Connect the F-SD connector on a link module to the F-RD connector on the next module and connect the R-RD connector on a link module to the R-SD connector of the next module.
Page 236 PROCEDURES TO OPERATION Disconnecting coaxial cable The following flowchart shows a method for disconnecting coaxial cables. Disconnection Link module Plug Turn OFF the power supply. Rotate a plug in the arrow direction to loosen the connection. Hold the plug and pull it out in the arrow direction shown below.
Page 237: Shielded Twisted Pair Cable Wiring
PROCEDURES TO OPERATION Shielded Twisted Pair Cable Wiring This section describes a connection method for shielded twisted pair cables. 8.5.1 Precautions for wiring The following shows the precautions when wiring shielded twisted pair cables in MELSECNET/B data link system. Laying shielded twisted pair cables When laying shielded twisted pair cables, follow the precautions below to prevent extraneous noise and surge induction.
Page 238: Connecting Shielded Twisted Pair Cables
PROCEDURES TO OPERATION 8.5.2 Connecting shielded twisted pair cables Wire shielded twisted pair cables to link modules as shown in Fig 8.12. Connect terminal resistors to both end stations. Fig 8.12 Connecting shielded twisted pair cables to link modules REMARK Use M4-size terminal screws for terminal blocks that connect shielded twisted pair cables.
Page 239: Startup Procedure
MELSECNET mode MELSECNET MELSECNET/B MELSECNET MELSECNET MELSECNET MELSECNET MELSECNET MELSECNET Operating Mode mode composite mode mode mode composite mode mode PROCEDURES TO OPERATION Applicability Startup Procedure In MELSECNET data link system, the power supplies have to be turned on simultaneously or in the order of system from lowest to highest.
Page 240: Self-Diagnostics Test
MELSECNET mode MELSECNET MELSECNET/B MELSECNET MELSECNET MELSECNET MELSECNET MELSECNET MELSECNET Operating Mode mode composite mode mode mode composite mode mode PROCEDURES TO OPERATION Applicability Self-diagnostics Test The self-diagnostics test checks link module hardware and link cables for wire break. The following five items are checked with the self-diagnostics test: Test name Description MELSECNET...
Page 241 PROCEDURES TO OPERATION Test procedure The following flowchart shows the operation procedure for self-loopback test. Test result The LEDs on the link module indicate the test result. The descriptions of the LEDs are as follows. (a) Normal..The following LEDs flash in order: CRC, OVER, AB.IF, TIME, DATA, UNDER (b) Error...The corresponding LEDs turn ON and the test is discontinued.
Page 242: Station To Station Test
MELSECNET mode MELSECNET MELSECNET/B MELSECNET MELSECNET MELSECNET MELSECNET MELSECNET MELSECNET Operating Mode mode composite mode mode mode composite mode mode PROCEDURES TO OPERATION Applicability 8.7.2 Station to station test Station to station test The station to station test checks the cable connections of two adjacent stations. When the data sent from the master station link module is not returned from the slave station link module in a given time, the loop is determined to be faulty.
Page 243 PROCEDURES TO OPERATION Test procedure The following flowchart shows the operation procedure for station to station test. Test result The LEDs indicate the test result. The descriptions of the LEDs are as follows. (a) Normal... The following LEDs flash in order: CRC, OVER, AB.IF, TIME, DATA, UNDER (b) Error..The corresponding LEDs turn ON and the test is discontinued.
Page 244: Forward Loop Test And Reverse Loop Test
MELSECNET mode MELSECNET MELSECNET/B MELSECNET MELSECNET MELSECNET MELSECNET MELSECNET MELSECNET Operating Mode mode composite mode mode mode composite mode mode PROCEDURES TO OPERATION Applicability 8.7.3 Forward loop test and reverse loop test POINT The forward/reverse loop tests require data link parameter. Write data link parameter setting of only the total number of slave stations to the master station.
Page 245 PROCEDURES TO OPERATION Reverse loop test (a) The reverse loop test checks the reverse loop in MELSECNET data link system after optical fiber cables or coaxial cables are laid down. (b) When the receive end of the reverse loop in the master station cannot receive data sent from the send end of the reverse loop in the master station, the loop is determined to be faulty.
Page 246 PROCEDURES TO OPERATION Test procedure The following flowchart shows the operation procedure for forward loop test/reverse loop test. Test result The LEDs on the link module of the master station or the GPP link monitor function show(s) the test result. (a) For GPP link monitor, refer to Section 10.1.
Page 247: Programming
MELSECNET mode MELSECNET MELSECNET/B MELSECNET MELSECNET MELSECNET MELSECNET MELSECNET MELSECNET Operating Mode mode composite mode mode mode composite mode mode PROGRAMMING Applicability PROGRAMMING This chapter describes methods for programming the master and local stations to perform data link among CPU modules. Precautions for Creating Programs Used link devices The device numbers assigned to each station with link parameter can be used for link...
Page 248 PROGRAMMING (b) Set link refresh disable area as shown below when using a module which can make rink refresh execution disable setting such as the AnNCPUP21/R21 by using ON/OFF of M9053 and the DI/EI instructions. (c) The module that performs link refresh only after the execution of the END instruction in the sequence program (A3HCPU, A3MCPU, AnACPU, AnUCPU, A2USCPU(S1), QnACPU, QnAS(H)CPU(S1)), even if data of two words or more are sent to link registers, the old and new data are not mixed.
Page 249 PROGRAMMING (b) If a receive error occurs while the RFRP or RTOP instruction is being executed, the handshake signals (YnE, YnF) may remain ON. Therefore, create a ladder so that the handshake signals (YnE, YnF) and the special function module error signal (X(n+1)D) are turned OFF in case of a communication error.
Page 250: Special Link Relays
MELSECNET mode MELSECNET MELSECNET/B MELSECNET MELSECNET MELSECNET MELSECNET MELSECNET MELSECNET Operating Mode mode composite mode mode mode composite mode mode PROGRAMMING Applicability Special Link Relays Special link relays are internal relays controlled by turning ON/OFF due to various causes during data link. Monitoring or using them in a sequence program can check data link errors.
Page 251 PROGRAMMING Table 9.1 MELSECNET special link relays list (Continued) Device Name Data Description Number Link parameter OFF : Check • Turned ON when the link devices (B and W) used by the upper tier and check instruction executed lower tier are not compared for "match". M9209 (lower tier link ON : Check not...
Page 252 PROGRAMMING Table 9.1 MELSECNET special link relays list (Continued) Device Name Data Description Number • Turned ON when a local station in the executed loop detects an error in OFF : No error another station (M9255 ON). Local station error M9233 ON : Error •...
Page 253 PROGRAMMING Table 9.2 MELSECNET/B special link relays list Device Name Data Description Number • Turned ON when an LRDP (word device read) instruction is received. • Used in a user program as an interlock for an LRDP instruction. LRDP instruction OFF : Unreceived M9200 •...
Page 254 PROGRAMMING Table 9.2 MELSECNET/B special link relays list (Continued) Device Name Data Description Number OFF : RUN or • ON/OFF status depends on the operation status of the local station. STEP RUN • Turned ON when the status of any local station in the loop changes to Local station status STOP or PAUSE.
Page 255: Special Link Relays Enabled Only For Local Stations
MELSECNET mode MELSECNET MELSECNET/B MELSECNET MELSECNET MELSECNET MELSECNET MELSECNET MELSECNET Operating Mode mode composite mode mode mode mode composite mode PROGRAMMING Applicability 9.2.2 Special link relays enabled only for local stations Table 9.3 and Table 9.4 show the special relays controlled only when the host station is set to local station.
Page 256 PROGRAMMING Table 9.3 MELSECNET special link relays list (Continued) Device Name Data Description Number • ON/OFF status depends on whether the station itself stopped the data link. • Turned ON when the data link is established in neither the forward loop line OFF : Normal M9251 Link halt...
Page 257 PROGRAMMING Table 9.4 MELSECNET/B special link relays list Device Name Data Description Number LRDP instruction OFF : Uncompleted • Turned ON by a local station upon the completion of word device read M9204 completed ON : Completed processing called by an LRDP instruction. LWTP instruction OFF : Uncompleted •...
Page 258: Special Link Registers
MELSECNET mode MELSECNET MELSECNET/B MELSECNET MELSECNET MELSECNET MELSECNET MELSECNET MELSECNET Operating Mode mode composite mode mode mode composite mode mode PROGRAMMING Applicability Special Link Registers Special link registers store causes of errors that occur at the time of data link in the form of value.
Page 259 PROGRAMMING Table 9.5 List of MELSECNET special link registers (Continued) Device Name Data Description Number Stores whether a slave station is compatible with the MELSECNET Stores the status of No.1 to D9202 No.16 mode or MELSECNET mode. • MELSECNET -compatible station : "1" •...
Page 260 PROGRAMMING Table 9.5 List of MELSECNET special link registers (Continued) Device Name Data Description Number Stores the current path of the data link. (1) Forward loop (2) Reverse loop • Forward/reverse loop 0 : Data link in forward loop 1 : Data link in reverse loop 2 : Loopback in forward/ reverse direction D9204...
Page 261 PROGRAMMING Table 9.5 List of MELSECNET special link registers (Continued) Device Name Data Description Number • Stores the number of local station or remote I/O station at which loopback is being executed. Loopback Station executing forward D9205 execution station loopback Example: "1"...
Page 262 PROGRAMMING Table 9.5 List of MELSECNET special link registers (Continued) Device Name Data Description Number • Stores the station No. of STOP- or PAUSE-status local station(s) as shown Stores the status of below. D9212 No.1 to No.16 Stores the status of D9213 No.17 to No.32 •...
Page 263 PROGRAMMING Device Name Data Description Number • Stores the numbers of the stations at which a link parameter error sent Stores the status of from the master station is detected by another local or remote I/O station. D9220 No.1 to No.16 Stores the status of D9221 No.17 to No.32...
Page 264 PROGRAMMING Table 9.5 List of MELSECNET special link registers (Continued) Device Name Data Description Number • Stores station Nos. of local stations or remote I/O stations, which are exchanging initial setting data for data link processing, into Stores the status of D9224 the corresponding bits in D9224 to D9227 as shown below.
Page 265 PROGRAMMING Table 9.5 List of MELSECNET special link registers (Continued) Device Name Data Description Number • Stores the station number of the local and remote I/O stations at which an error is detected in the forward loop line or reverse loop Stores the status of D9232 line.
Page 266 PROGRAMMING Table 9.6 List of MELSECNET/B special link registers Device Name Data Description Number Stores the execution result of an LRDP (word device read) instruction (M9201 ON). • LRDP instruction setting fault: ........Faulty setting of the LRDP 0 : Normal instruction constant, source, and/or 2 : LRDP instruction setting target...
Page 267 PROGRAMMING Table 9.6 List of MELSECNET/B special link registers (Continued) Device Name Data Description Number D9207 Maximum value • Stores the time used for data link processing (link scan time) by all of the local stations and remote I/O stations in the loop currently being used for data link.
Page 268 PROGRAMMING Table 9.6 List of MELSECNET/B special link registers (Continued) Device Name Data Description Number • Stores the station No. of all local stations that are in a STOP or PAUSE status. Stores the status of D9212 No.1 to No.16 Local station operating status •...
Page 269 PROGRAMMING Table 9.6 List of MELSECNET/B special link registers (Continued) Device Name Data Description Number • Stores station Nos. of local stations or remote I/O stations communicating initial setting data for data link processing into the corresponding bits in D9224 to D9227 as shown below. Stores the status of D9224 No.1 to No.16...
Page 270: Special Link Registers Effective Only For Local Stations
MELSECNET mode MELSECNET MELSECNET/B MELSECNET MELSECNET MELSECNET MELSECNET MELSECNET MELSECNET Operating Mode mode composite mode mode mode composite mode mode PROGRAMMING Applicability 9.3.2 Special link registers effective only for local stations Table 9.7 and Table 9.8 show the special registers controlled only when the host station is set to the master station.
Page 271 PROGRAMMING Table 9.8 List of MELSECNET/B special link registers Device Name Data Description Number Station number Stores a station number • Stores the station number assigned to the host station itself. D9243 data of the station (0 to 64) • Used by a local station to check the host station number. itself Slave station Stores a slave station...
Page 272: Data Link Program Using Link Inputs (X) And Link Outputs (Y)
MELSECNET mode MELSECNET MELSECNET/B MELSECNET MELSECNET MELSECNET MELSECNET MELSECNET MELSECNET Operating Mode mode composite mode mode composite mode mode mode PROGRAMMING Applicability Data Link Program Using Link Inputs (X) and Link Outputs (Y) This section explains the programming method for data link between the master station and local station and between the master station and remote I/O station using link inputs (X) and link outputs (Y).
Page 273 PROGRAMMING [Link device assignment] Fig 9.2 Link device assignment 9 - 27...
Page 274 PROGRAMMING [Program example 1] ..Data link between the master station and a local station Master station program Turn Y260 (X1B0 of local station No.3) ON while the T4 contact is OFF and turn Y390 (X250 of local station No.2) ON while the T4 contact is ON. Turn YC0 ON while X1A0 (Y210 of local station No.2) is ON, and turn YC1 ON while X2A0 (Y300 of local station No.3) is ON.
Page 275 PROGRAMMING [Program example No.2]..Data link between the master station and a remote I/O station Master station program When X0 (X6D0 of master station) of remote I/O station No.1 is turned ON, Y120 (Y7F0 of the master station) of remote I/O station No.1 and Y170 (Y670 of the master station) of remote I/O station No.4 flash every 1 second.
Page 276: Data Link Program Using Link Relays (B)
MELSECNET mode MELSECNET MELSECNET/B MELSECNET MELSECNET MELSECNET MELSECNET MELSECNET MELSECNET Operating Mode mode composite mode mode mode composite mode mode PROGRAMMING Applicability Data Link Program Using Link Relays (B) This section presents a program for sequentially turning ON "Y140" of the master station, "YC0"...
Page 277 PROGRAMMING [Link device assignment] Fig 9.4 Link device assignment 9 - 31...
Page 278 PROGRAMMING [Program example] Master station program Turn Y140 and B0 ON when T1 times out and turn Y140 and B0 OFF 1 second after BE0 is turned ON. (B0: ON/OFF instruction for YC0 of local station No.2) Local station No.2 program Turn YC0 and B60 ON 1 second after B0 of the master station is turned ON.
Page 279: Data Link Program Using Link Registers (W)
MELSECNET mode MELSECNET MELSECNET/B MELSECNET MELSECNET MELSECNET MELSECNET MELSECNET MELSECNET Operating Mode mode composite mode mode mode composite mode mode PROGRAMMING Applicability Data Link Program Using Link Registers (W) The following describes a program where the link register contents (0 to 10) written by the master station are read by the local station No.2 and "YD0"...
Page 280 PROGRAMMING [Link device assignment] Fig 9.6 Link device assignment 9 - 34...
Page 281 PROGRAMMING [Program example] Master station program A program to store "0 to 10" to W0. (B10 and B11 are used for handshaking of the master station and local station No.2.) Local station No.2 program Turn YD0, YD1, and YD2 ON when the W0 data is transferred from the master station YD0 ..
Page 282: Read/Write Program For A Word Device From The Master Station To A Local Station
MELSECNET mode MELSECNET MELSECNET/B MELSECNET MELSECNET MELSECNET MELSECNET MELSECNET MELSECNET Operating Mode mode composite mode mode mode composite mode mode PROGRAMMING Applicability Read/Write Program for a Word Device from the Master Station to a Local Station The following describes a program where data is read from/written to the word device of the local station from the master station using the LRDP/LWTP instruction.
Page 283 PROGRAMMING [Link device assignment] Fig 9.8 Link device assignment 9 - 37...
Page 284 PROGRAMMING Read program (LRDP instruction) The following describes program where the present value of C50 to C55 of local station No.2 is read to D100 to D105 of the master station. (For system configuration and link parameter setting, refer to Fig 9.7 and Fig 9.8.) [Program example] Executed only when the read command is turned ON Executed while the read command is ON...
Page 285 PROGRAMMING Write program (LWTP instruction) The following describes the program where the present value of C0 to C9 of the master station is written to C0 to C9 of the local station No.3. (For system configuration and link parameter setting, refer to Fig 9.7 and Fig 9.8.) [Program example] For execution only when the write command status is changed from OFF to ON Executed while the write command is ON...
Page 286: Read/Write Program From A Remote I/O Station To A Special Function Module
MELSECNET mode MELSECNET MELSECNET/B MELSECNET MELSECNET MELSECNET MELSECNET MELSECNET MELSECNET Operating Mode mode composite mode mode composite mode mode mode PROGRAMMING Applicability Read/Write Program from a Remote I/O Station to a Special Function Module This section describes the programming method to read/write data of a special function module installed to a remote I/O station from the master station.
Page 287 PROGRAMMING [Link device assignment] Fig 9.10 Link device assignment REMARK In the M R area of remote I/O stations No.1 and No.4, two points (W200 and W201, W250 and W251) from the head device are used by the system. These points cannot be used for a user program.
Page 288: Read Program (Rfrp Instruction)
MELSECNET mode MELSECNET MELSECNET/B MELSECNET MELSECNET MELSECNET MELSECNET MELSECNET MELSECNET Operating Mode mode composite mode mode composite mode mode mode PROGRAMMING Applicability 9.8.1 Read program (RFRP instruction) This is a program to read the data of the special function module mounted on the remote I/O station No.
Page 289 PROGRAMMING (2) Executed always while the start signal is ON 9 - 43...
Page 290 PROGRAMMING NOTE To execute an RFRP instruction, always interlock with Y E and X( ) E (n: the device number of the master station that corresponds to the I/O number of the slot in which a special function module is installed. It is first 2 digits of the 3-digit representation for the first half link parameters 16 points of 32 occupied points.), and at the same time, do not execute an RFRP or RTOP instruction at two or more positions within a single special function module.
Page 291 PROGRAMMING Write an error detection circuit in a sequence program to check the operation from error occurrence to initial communication completion when an error occurs to a local or remote I/O station. (a) Whether an error has occurred in a local or remote I/O station or not can be determined by 1/0 of bit corresponding to the specified station of D9228 to D9231.
Page 292: Write Program (Rtop Instruction)
MELSECNET mode MELSECNET MELSECNET/B MELSECNET MELSECNET MELSECNET MELSECNET MELSECNET MELSECNET Operating Mode mode composite mode mode composite mode mode mode PROGRAMMING Applicability 9.8.2 Write program (RTOP instruction) The following shows the program where data is written to the special function module installed to remote I/O station No.4.
Page 293 PROGRAMMING (2) Executed always while the start signal is ON 9 - 47...
Page 294 PROGRAMMING PRECAUTIONS To execute an RTOP instruction, always interlock with YnF and X F (n: the device (n+1) number of the master station that corresponds to the I/O number of the slot in which a special function module is installed. It is first 2 digits of the 3-digit representation for the first half link parameters 16 points of 32 occupied points.), and at the same time, do not execute an RFRP or RTOP instruction at two or more positions within a single special function module.
Page 295 PROGRAMMING Write an error detection circuit in a sequence program to check the operation from error occurrence to initial communication completion when an error occurs to a local or remote I/O station. (a) Whether an error has occurred in a local or remote I/O station or not can be determined by 1/0 of bit corresponding to the specified station of D9228 to D9231.
Page 296: Fault Detection Program
MELSECNET mode MELSECNET MELSECNET/B MELSECNET MELSECNET MELSECNET MELSECNET MELSECNET MELSECNET Operating Mode mode composite mode mode mode composite mode mode PROGRAMMING Applicability Fault Detection Program The following shows a program with which a faulty station is detected by the master station when an error occurs in any of the local/remote I/O stations No.
Page 297 PROGRAMMING [Link device assignment] Fig 9.12 Link device assignment 9 - 51...
Page 298 PROGRAMMING [Program example] 9 - 52...
Page 299: Troubleshooting
MELSECNET mode MELSECNET MELSECNET/B MELSECNET MELSECNET MELSECNET MELSECNET MELSECNET MELSECNET Operating Mode mode composite mode mode mode composite mode mode 10. TROUBLESHOOTING Applicability TROUBLESHOOTING To improve the reliability of the system, it is very important to use reliable equipment. In addition, the other very important factor is whether or not to recover from failure immediately and certainly.
Page 300: Master Station Link Monitor
MELSECNET mode MELSECNET MELSECNET/B MELSECNET MELSECNET MELSECNET MELSECNET MELSECNET MELSECNET Operating Mode mode composite mode mode mode composite mode mode 10. TROUBLESHOOTING Applicability 10.1.1 Master station link monitor The following describes the link monitor when connecting GPP to the master station. A6GPP Fig 10.1 Master station link monitor screen (when connecting to master station) 10 - 2...
Page 301 TROUBLESHOOTING Displaying host station operation mode (M9224, M9227) (a) Displays operation status of the master station 1) ON-LINE: Master station mode setting is ON-LINE (with/without automatic return function). 2) OFF-LINE: Master station mode setting is OFF-LINE, SELF-LOOPBACK TEST, or STATION-TO-STATION TEST. 3) LOOP TEST: Master station mode setting is FORWARD LOOP TEST or REVERSE LOOP TEST.
Page 302 10. TROUBLESHOOTING (b) The loop status and loopback execution station are the same as the following registers: 1) Loop status:......D9204 2) Loopback execution station:... D9205, D9206 Operation status of all slave stations (local and remote I/O stations) The status of all of the slave stations in the system is displayed as follows: "L"...
Page 303 TROUBLESHOOTING "A" column: An error will occur to the master station for the third tier if there is an error in the third tier link parameters set for the corresponding station.(D9220 to D9223) When the both inputs (X) and outputs (Y) are not set to a remote I/O station with link parameters or when I/O assignment of the master station and installation position of the I/O module of the host station are wrong, an error will occur.
Page 304: Local Station Link Monitor
MELSECNET mode MELSECNET MELSECNET/B MELSECNET MELSECNET MELSECNET MELSECNET MELSECNET MELSECNET Operating Mode mode composite mode mode mode composite mode mode 10. TROUBLESHOOTING Applicability 10.1.2 Local station link monitor The following describes the link monitor when connecting GPP to the local station. A6GPP Fig 10.2 Local station link monitor screen (when connecting to local station) 10 - 6...
Page 305 TROUBLESHOOTING Displaying operation mode of the host station (a) Displays the operation status of host station 1) ON-LINE..Host station mode setting is ON-LINE (automatic return function set/not set). 2) OFF-LINE..Host station mode setting is OFF-LINE, SELF-LOOPBACK TEST, or STATION-TO-STATION TEST. 3) LOOP TEST...Host station mode setting is FORWARD LOOP TEST or REVERSE LOOP TEST.
Page 306 10. TROUBLESHOOTING Displaying B/W receive status (local station in three-tier system) (M9247) (a) Displays whether a local station in the three-tier system is receiving the link relays (B) and link registers (W) from the master station in the two-tier system. 1) OK (receiving)..B and W are being received from the master station in the two-tier system by the cyclic communication.
Page 307: Remote I/O Station Link Monitor
MELSECNET mode MELSECNET MELSECNET/B MELSECNET MELSECNET MELSECNET MELSECNET MELSECNET MELSECNET Operating Mode mode composite mode mode composite mode mode mode TROUBLESHOOTING Applicability 10.1.3 Remote I/O station link monitor This section describes the following link monitor when connecting GPP to a remote I/O station.
Page 308 10. TROUBLESHOOTING Displaying loop line status of the host station (a) Displays the forward loop line (F loop) and reverse loop line (R loop) status of the host station. 1) OK..Loop line is normal. 2) NG..Loop line is faulty. Displaying loopback execution status (a) Displays whether loopback has been executed by the host station or not.
Page 309 TROUBLESHOOTING Displaying station number Displays the station number of the remote I/O station connected to the GPP. Displaying number of slave stations Displays the total number of local and remote I/O stations connected in the loop. Batch Monitor The following describes the batch monitor when connecting GPP to a remote I/O station.
Page 310 10. TROUBLESHOOTING Displaying ON/OFF status of inputs (X) (a) Displays the ON/OFF status of inputs (X) sent from a remote I/O station to the master station..ON status ..OFF status (b) If the remote I/O station is online, the device numbers at the master station are used for the display.
Page 311: Monitoring The Special Link Relays And Special Link Registers
MELSECNET mode MELSECNET MELSECNET/B MELSECNET MELSECNET MELSECNET MELSECNET MELSECNET MELSECNET Operating Mode mode composite mode mode mode composite mode mode TROUBLESHOOTING Applicability 10.2 Monitoring the Special Link Relays and Special Link Registers Faulty stations in the MELSECNET data link system can be detected by using the A7PU to monitor the special link relays and special link registers.
Page 312: Procedure For Troubleshooting
MELSECNET mode MELSECNET MELSECNET/B MELSECNET MELSECNET MELSECNET MELSECNET MELSECNET MELSECNET Operating Mode mode composite mode mode mode composite mode mode 10. TROUBLESHOOTING Applicability 10.3 Procedure for Troubleshooting The following describes the simple procedure for troubleshooting. 10.3.1 Troubleshooting flowchart 10 - 14...
Page 313: Flowchart For When "The Data Link Is Disabled Throughout The Entire System
MELSECNET mode MELSECNET MELSECNET/B MELSECNET MELSECNET MELSECNET MELSECNET MELSECNET MELSECNET Operating Mode mode composite mode mode mode composite mode mode TROUBLESHOOTING Applicability 10.3.2 Flowchart for when "the data link is disabled throughout the entire system" 10 - 15...
Page 314 10. TROUBLESHOOTING POINT (1) In the MELSECNET data link, if the power supply of the local or remote I/O station on both sides of a normally operating local or remote I/O station is turned off simultaneously (within 100 ms), the data link for the entire system might be disabled.
Page 315: Flowchart For When "The Data Link Is Disabled At A Specific Station
MELSECNET mode MELSECNET MELSECNET/B MELSECNET MELSECNET MELSECNET MELSECNET MELSECNET MELSECNET Operating Mode mode composite mode mode mode composite mode mode TROUBLESHOOTING Applicability 10.3.3 Flowchart for when "the data link is disabled at a specific station" 10 - 17...
Page 316 10. TROUBLESHOOTING 10 - 18...
Page 317: Flowchart For When "The Data Communication Error Occurs
MELSECNET mode MELSECNET MELSECNET/B MELSECNET MELSECNET MELSECNET MELSECNET MELSECNET MELSECNET Operating Mode mode composite mode mode mode composite mode mode TROUBLESHOOTING Applicability 10.3.4 Flowchart for when "the data communication error occurs" 10 - 19...
Page 318 10. TROUBLESHOOTING 10 - 20...
Page 319 TROUBLESHOOTING 10 - 21...
Page 320 10. TROUBLESHOOTING 10 - 22...
Page 321 TROUBLESHOOTING 10 - 23...
Page 322: Flowchart For When "The Unspecified Number Of Slave Stations Become Faulty
MELSECNET mode MELSECNET MELSECNET/B MELSECNET MELSECNET MELSECNET MELSECNET MELSECNET MELSECNET Operating Mode mode composite mode mode mode composite mode mode 10. TROUBLESHOOTING Applicability 10.3.5 Flowchart for when "the unspecified number of slave stations become faulty" 10 - 24...
Page 323: Error Led
MELSECNET mode MELSECNET MELSECNET/B MELSECNET MELSECNET MELSECNET MELSECNET MELSECNET MELSECNET Operating Mode mode composite mode mode mode composite mode mode TROUBLESHOOTING Applicability 10.4 ERROR LED The following describes LED which turns ON when an error occurs during data link execution. Error- Indication Name...
Page 324: Replacing A Faulty Station Of Link Module
10. TROUBLESHOOTING 10.5 Replacing a Faulty Station of Link Module This section explains how to replace the link module of a faulty station in data link system. When a MELSECNET data link system is used Since the link cables are doubled in a MELSECNET data link system, the loopback function can continue data link operations even if power supply to one station (local or remote I/O station) is turned OFF.
Page 325 TROUBLESHOOTING When a MELSECNET/B data link system is used In a MELSECNET/B data link system, since the link cables for both send and receive operations are connected to the same terminal block, data link operations can be continued even if power supply to one of the local stations is turned OFF. Replace the link module of a faulty station as shown below: 10 - 27...
Page 326 INDEX Using MELSECNET mode....7-11,7-24 Assignment of link devices for a Three-Tier System Link refresh execution timing ......6-2 ................ 7-61 Link refresh time..........6-11 Automatic return function......5-4,5-17 Link register..........5-27,7-21 Link relay ..........5-27,7-20 Local station ............1-3 Local/remote I/O system assignment ....7-52 Coaxial cable ..........
Page 327 Remote I/O system assignment ..... 7-50 Reverse loop test..........8-21 Self-diagnostics function......5-26,8-17 Self-loopback test ........... 8-17 Setting of the Number of Modules ....7-2 Setting the link module station numbers... 8-2 Slave stations ..........2-1,3-1 Special link register ........9-12 Special link relay..........
Page 328 6. Failure caused by reasons unpredictable by scientific technology standards at time of shipment from Mitsubishi. 7. Any other failure found not to be the responsibility of Mitsubishi or that admitted not to be so by the user. 2. Onerous repair term after discontinuation of production (1) Mitsubishi shall accept onerous product repairs for seven (7) years after production of the product is discontinued.

Mitsubishi MELSEC-A Series Reference Manual

1 Overview

2 Two-Tier System in the Melsecnet Data Link System

3 Two-Tier System in the Melsecnet/B Data Link System

4 Composition of a Three-Tier System

5 Specifications

6 Link Data Send/Receive Processing and Processing Time

7 Data Link Settings

8 Procedures to Operation

9 Programming

10 Troubleshooting

Quick Links

Troubleshooting

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Summary of Contents for Mitsubishi MELSEC-A Series

Table of Contents