Mitsubishi Electric MELSEC FX Series User Manual
  1. Manuals
  2. Brands
  3. Mitsubishi Electric Manuals
  4. Controller
  5. MELSEC FX Series
  6. User manual

Mitsubishi Electric MELSEC FX Series User Manual

Programmable controllers
Hide thumbs Also See for MELSEC FX Series:
Table of Contents

Advertisement

Quick Links

Download this manual See also: User Manual
MITSUBISHI ELECTRIC
Programmable Controllers
User's Manual
FX
-4LC
3U
01052010
INDUSTRIAL AUTOMATION
MITSUBISHI ELECTRIC
JY997D39101
Version B

Advertisement

Table of Contents
loading

Related Manuals for Mitsubishi Electric MELSEC FX Series

Summary of Contents for Mitsubishi Electric MELSEC FX Series

  • Page 1 MITSUBISHI ELECTRIC Programmable Controllers User's Manual -4LC 01052010 INDUSTRIAL AUTOMATION MITSUBISHI ELECTRIC JY997D39101 Version B...
  • Page 3 Safety Precautions (Read these precautions before using.) Before installation, operation, maintenance or inspection of this product, thoroughly read through and understand this manual and the associated manuals. Also, take care to handle the module properly and safely. This manual classifies the safety precautions into two categories: Indicates that incorrect handling may cause hazardous conditions, resulting in death or severe injury.
  • Page 4 Safety Precautions (Read these precautions before using.) 2. INSTALLATION PRECAUTIONS Reference • Make sure to shut down all phases of the power supply externally before installing. Failure to do so may cause electric shock or damage to the product. Reference •...
  • Page 5 • Do not disassemble or modify the PLC. Doing so may cause fire, equipment failures, or malfunctions. For repair, contact your local Mitsubishi Electric distributor. • Turn off the power to the PLC before connecting or disconnecting any extension cable.
  • Page 6 MEMO...

  • Page 7: Safety Precautions

    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. © 2010 MITSUBISHI ELECTRIC CORPORATION...
  • Page 8 • Since the examples within this manual, technical bulletin, catalog, etc. are used as reference; please use it after confirming the function and safety of the equipment and system. Mitsubishi Electric will not accept responsibility for actual use of the product based on these illustrative examples.

  • Page 9: Table Of Contents

    -4LC User's Manual Table of Contents SAFETY PRECAUTIONS ....................(1) Standards........................... 7 Certification of UL, cUL standards ....................... 7 Compliance with EC directive (CE Marking) ..................7 Associated Manuals........................9 Generic Names and Abbreviations Used in the Manual ............11 Reading the Manual ........................
  • Page 10 -4LC User's Manual 6. Introduction of Functions 6.1 Functions List ..........................33 6.2 Control Mode Switch Function ...................... 34 6.3 Transistor Output Selection Function.................... 36 6.4 PID control ............................ 38 6.4.1 Easy PID control with two degrees of freedom................38 6.4.2 Overshoot prevention function.......................
  • Page 11 -4LC User's Manual 8. Buffer Memory 8.1 Buffer Memory List ........................73 8.2 Buffer Memory Details........................77 8.2.1 [BFM#0] Flag ..........................77 8.2.2 [BFM#1 to 4] Event........................78 8.2.3 [BFM#5 to 8] Measured value (PV) ....................79 8.2.4 [BFM#9 to 12] Control output value (MV) monitor/ Heating control output value (MV) monitor ................
  • Page 12 -4LC User's Manual 8.2.54 [BFM#232] Cooling method setting ................... 112 8.2.55 [BFM#233] Alarm dead band setting ..................113 8.2.56 [BFM#234] Alarm delay count ....................114 8.2.57 [BFM#235] Number of times of heater disconnection alarm delay/ Number of times of current error detection when output is OFF delay ........115 8.2.58 [BFM#236] Temperature rise completion range setting ............

  • Page 13: Standards

    • Manufactured by: Mitsubishi Electric Corporation 2-7-3 Marunouchi, Chiyoda-ku, Tokyo, 100-8310 Japan • Manufactured at: Mitsubishi Electric Corporation Himeji Works 840 Chiyoda-machi, Himeji, Hyogo, 670-8677 Japan • Authorized Representative in the European Community: Mitsubishi Electric Europe B.V. Gothaer Str. 8, 40880 Ratingen, Germany...
  • Page 14 (integral with sensors or actuators), these users should follow those manufacturers installation requirements. Mitsubishi Electric recommend that shielded cables should be used. If NO other EMC protection is provided, then users may experience temporary loss or accuracy between ±10% in very heavy industrial areas.

  • Page 15: Associated Manuals

    -4LC User's Manual Associated Manuals Associated Manuals Only the installation manual is packed together with the FX -4LC temperature control block. For a detailed explanation of the FX -4LC temperature control block, refer to this manual. For the hardware information and instructions on the PLC main unit, refer to the respective manuals. Refer to these manuals Refer to the appropriate equipment manual For a detailed explanation, refer to an additional manual...
  • Page 16 -4LC User's Manual Associated Manuals Document Title of manual Description Model code number Manuals for FX -4LC temperature control block Describes installation specifications for the FX -4LC Supplied -4LC temperature control block extracted from the FX -4LC JY997D38901 Manual Installation Manual User's Manual.

  • Page 17: Generic Names And Abbreviations Used In The Manual

    -4LC User's Manual Generic Names and Abbreviations Used in the Manual Generic Names and Abbreviations Used in the Manual Generic name or abbreviation Description series Generic name for FX Series PLC PLC or main unit Generic name for FX Series PLC main unit series Generic name for FX Series PLC...
  • Page 18 -4LC User's Manual Generic Names and Abbreviations Used in the Manual Generic name or abbreviation Description Manual Hardware Edition Series User's Manual - Hardware Edition Hardware Edition Series User's Manual - Hardware Edition Hardware Edition Series User's Manual - Hardware Edition Programming manual Series Programming Manual - Basic and Applied Instructions Edition Communication control Edition...

  • Page 19: Reading The Manual

    -4LC User's Manual Reading the Manual Reading the Manual In this manual, the following formats are used for describing the common items. Indexes the chapter number. Shows the title of the chapter and the title Shows the manual title. of the section. The right side of each page This area shows the indexes the chapter number...

  • Page 20: Introduction

    1 Introduction -4LC User's Manual 1.1 Outline Introduction Outline The temperature control block FX -4LC (hereinafter called 4LC) equipped with 4 channel input (thermocouples, resistance thermometer and micro voltage input), 4 points output (open collector transistor) and 4 points CT input is a special function block for thermometer control. 1.1.1 Major features of the FX -4LC...

  • Page 21: External Dimensions And Part Names

    1 Introduction -4LC User's Manual 1.2 External Dimensions and Part Names External Dimensions and Part Names 2-Ø4.5mounting holes [4] [5] [1] [2] 82(3.23") (mounting hole pitch) 9(0.36") 90(3.55") 86(3.39") [Without cover] [10] [11] [12] [13] Unit: mm(inches) MASS(Weight): 0.4kg(0.88lbs) Accessaries: Label for indication of special unit/block number, Dust proof sheet, Manual supplied with product [11]...

  • Page 22: Terminal Layout

    1 Introduction -4LC User's Manual 1.3 Terminal Layout Terminal Layout OUT1 OUT2 PTB/TC-/COM PTB/TC-/COM PTA/ / PTA/ / COM1 PTB/TC+/VL+ PTB/TC+/VL+ OUT3 OUT4 PTB/TC-/COM PTB/TC-/COM PTA/ / PTA/ / COM2 PTB/TC+/VL+ PTB/TC+/VL+ Power and Status LEDs LED display Color Status Description Power is not being supplied from the internal power supply (5V DC).

  • Page 23: Specification

    2 Specification -4LC User's Manual Specification DESIGN PRECAUTIONS • Make sure to include the following safety circuits outside the PLC to ensure safe system operation even during external power supply problems or PLC failure. Otherwise, malfunctions may cause serious accidents. 1) Above all, the following components should be included: an emergency stop circuit, a protection circuit, an interlock circuit for opposite movements (such as normal vs.

  • Page 24: General Specifications

    2 Specification -4LC User's Manual 2.1 General Specifications General Specifications For items not listed below, specifications are the same as the of the PLC main unit. For general specifications, refer to the manual of the PLC main unit. → Refer to FX Hardware Edition.

  • Page 25: Input Specifications

    2 Specification -4LC User's Manual 2.4 Input Specifications Input Specifications 2.4.1 Temperature input specifications Item Specification Number of input points 4 points K, J, R, S, E, T, B, N JIS C 1602-1995 Thermocouple PLII, W5Re/W26Re, U, L 3-wire Pt100 JIS C 1604-1997 Input type Resistance thermometer 3-wire JPt100 JIS C 1604-1981...

  • Page 26: Measurement Precision

    2 Specification -4LC User's Manual 2.4 Input Specifications 2.4.2 Measurement precision The measurement precision is as shown below. The measurement precision of the thermocouple does not include the cold contact temperature compensation error. For the cold contact temperature compensation error, refer to Subsection 2.4.1. Digits below the minimum resolution (shown in the measurement precision below) of the input value are rounded up.

  • Page 27: Input Type

    2 Specification -4LC User's Manual 2.5 Input Type Input Type Input type -200.0 to 200.0 C -200.0 to 200.0 C -100.0 to 400.0 C -100.0 to 400.0 C -100.0 to 800.0 C 0 to 1700 C 0 to 1700 C Input range -100 to 1300 C -100 to 1200 C...

  • Page 28: System Configuration

    3 System Configuration -4LC User's Manual 3.1 General Configuration System Configuration General Configuration Analog Input/ Up to 8 can be connected analog output -4LC special function blocks GX Developer USB cable RS-232C cable -CNV-IF -1PS-5V For the maximum number, refer to Section 3.2. Component list Part name Model name...

  • Page 29: Applicable Plc

    3 System Configuration -4LC User's Manual 3.2 Applicable PLC Applicable PLC Model name Applicability Ver. 1.00 and later Series PLC (Up to 8 blocks can be connected) Ver. 2.20 and later Series PLC (Up to 8 blocks can be connected) Ver.

  • Page 30: Installation

    4 Installation -4LC User's Manual Installation INSTALLATION PRECAUTIONS • Make sure to shut down all phases of the power supply externally before installing. Failure to do so may cause electric shock or damage to the product. INSTALLATION PRECAUTIONS • Use the product within the generic environment specifications described in PLC main unit manual (Hardware Edition). Never use the product in areas with excessive dust, oily smoke, conductive dusts, corrosive gas (salt air, Cl S, SO , or NO...

  • Page 31: Din Rail Mounting

    4 Installation -4LC User's Manual 4.1 DIN rail Mounting DIN rail Mounting The product may be mounted on a 35mm wide DIN46277 (DIN rail). Fit the upper edge (A in the figure to the right) of the DIN rail mounting groove onto the DIN rail. Push the product onto the DIN rail.

  • Page 32: Direct Mounting

    4 Installation -4LC User's Manual 4.2 Direct Mounting Direct Mounting The product can be installed directly with screws. An interval space of 1 to 2mm (0.04" to 0.08") between each unit is necessary. For installation details, refer to the following respective PLC manual. →...

  • Page 33: Wiring

    5 Wiring -4LC User's Manual Wiring WIRING PRECAUTIONS • Make sure to cut off all phases of the power supply externally before attempting wiring work. Failure to do so may cause electric shock. WIRING PRECAUTIONS • Connect the AC power supply to the dedicated terminals specified in this manual. If an AC power supply is connected to a DC input/output terminal or DC power supply terminal, the PLC will burn out.

  • Page 34: Power Supply Wiring

    5 Wiring -4LC User's Manual 5.1 Power Supply Wiring Power Supply Wiring 5.1.1 Power supply wiring Stabilized Stabilized -CNV-IF power supply Grounding power supply Grounding 24V DC (Ground resistance: 24V DC -1PS-5V (Ground resistance: 100Ω or less) 100Ω or less) Grounding (Ground resistance: 100Ω...

  • Page 35: Input Wiring

    5 Wiring -4LC User's Manual 5.2 Input Wiring Input Wiring 5.2.1 Wiring example of thermocouple For thermocouples applicable to the 4LC, refer to the following. → Refer to the Section 2.4. -4LC 24V DC Grounding (Ground resistance: 100Ω or less) Compensating Thermocouple lead wire...

  • Page 36: Wiring Example Of Micro Voltage Input

    5 Wiring -4LC User's Manual 5.2 Input Wiring • When used the Pt1000 (2-wire) -4LC 24V DC Grounding (Ground resistance: 100Ω or less) Pt1000 Shielded cable Caution • When you use a resistance temperature sensor, the resistance of the leadwire is low, use a wire without a resistance difference between the leadwire.

  • Page 37: Output Wiring

    5 Wiring -4LC User's Manual 5.3 Output Wiring Output Wiring The 4LC incorporates NPN open collector transistor outputs. For the output specifications, refer to the following. → Refer to the Section 2.6. -4LC 24V DC Grounding (Ground resistance: 100Ω or less) COM1 Load OUT1...

  • Page 38: Terminal Screw And Tightening Torque

    5 Wiring -4LC User's Manual 5.4 Terminal Screw and Tightening Torque Terminal Screw and Tightening Torque The terminals on the 4LC use M3 screws. Refer to the figures below for cable end treatment. Tighten the terminals to a torque of 0.5 to 0.8 N•m. Do not tighten terminal screws with a torque exceeding the regulation torque.

  • Page 39: Introduction Of Functions

    6 Introduction of Functions -4LC User's Manual 6.1 Functions List Introduction of Functions Functions List The list below describes functions of the 4LC. Functions Description Reference Control mode switch function Selects the control type and used input/output for each control group. Section 6.2 Transistor output selection function Selects the function of transistor outputs built into the 4LC.

  • Page 40: Control Mode Switch Function

    6 Introduction of Functions -4LC User's Manual 6.2 Control Mode Switch Function Control Mode Switch Function The control mode switch function sets the control type (PID control, two-position control, manual control, cascade control or heating/cooling control) and used input/output (external or internal) for each control group. Make sure to set the control mode before performing control.
  • Page 41 6 Introduction of Functions -4LC User's Manual 6.2 Control Mode Switch Function Point When external input is selected, the following results are given. • Input range setting - The input span is "external input range upper limit"-"external input range lower limit". - The input range is from "external input range lower limit"...

  • Page 42: Transistor Output Selection Function

    6 Introduction of Functions -4LC User's Manual 6.3 Transistor Output Selection Function Transistor Output Selection Function The transistor output selection function selects either one among control output, alarm output and loop breaking alarm output for transistor outputs built into the 4LC. For example, when external outputs are used for control, transistor outputs built into the 4LC are not required, and can be used as alarm outputs.
  • Page 43 6 Introduction of Functions -4LC User's Manual 6.3 Transistor Output Selection Function Associated buffer memory BFM No. Description Reference CH1 CH2 CH3 CH4 Event (b4 to b7 Alarm 1 to Alarm 4) Subsection 8.2.2 (b8 Loop breaking alarm) Control output value (MV) monitor/ Subsection 8.2.4 Heating control output value (MV) monitor #16 Cooling control output value (MV) monitor...

  • Page 44: Pid Control

    6 Introduction of Functions -4LC User's Manual 6.4 PID control PID control 6.4.1 Easy PID control with two degrees of freedom PID control is a control method to obtain stable control result by setting each of the constants "P (proportional band)", "I (integral time)"...

  • Page 45: Overshoot Prevention Function

    6 Introduction of Functions -4LC User's Manual 6.4 PID control Associated buffer memory BFM No. Description Reference CH1 CH2 CH3 CH4 #138 #178 Proportional band (P)/Heating proportional band (P) Subsection 8.2.22 #100 #140 #180 Integral time (I) Subsection 8.2.24 #101 #141 #181 Derivative time (D) Subsection 8.2.25 #102 #142 #182 Control response parameter Subsection 8.2.26...

  • Page 46: Two-Position Control

    6 Introduction of Functions -4LC User's Manual 6.5 Two-position Control Two-position Control When the proportional band (P) or heating proportional band (P) value is set to "0", the 4LC performs two-position control. In two-position control, the control output (MV) is set to ON when the measured value (PV) is larger than the set value (SV) or OFF when the measured value (PV) is smaller than the set value (SV).

  • Page 47: Heating/Cooling Pid Control

    6 Introduction of Functions -4LC User's Manual 6.6 Heating/cooling PID control Heating/cooling PID control 6.6.1 Heating/cooling PID control Heating/cooling PID control handles two systems of outputs, heating control output and cooling control output. The heating side performs the reverse operation in which the control output (MV) decreases as the measured value (PV) increases, and the cooling side performs the normal operation in which the control output (MV) increases as the measured value (PV) increases.

  • Page 48: Overshoot Prevention Function

    6 Introduction of Functions -4LC User's Manual 6.6 Heating/cooling PID control Caution • Cascade control is disabled when heating/cooling PID control is selected. • The loop breaking alarm function is disabled in heating/cooling PID control. • The loop breaking alarm dead zone is invalid in heating/cooling PID control. •...

  • Page 49: Overlap/Dead Band Function

    6 Introduction of Functions -4LC User's Manual 6.6 Heating/cooling PID control 6.6.3 Overlap/dead band function The overlap/dead band function switches the significant point between control stability and energy saving by shifting the temperature at which cooling control is started. Overlap The overlap area indicates the temperature area where both heating output and cooling output are given.

  • Page 50: Cooling Method

    6 Introduction of Functions -4LC User's Manual 6.6 Heating/cooling PID control Associated buffer memory BFM No. Description Reference CH1 CH2 CH3 CH4 #138 #178 Proportional band (P)/Heating proportional band (P) Subsection 8.2.22 #139 #179 Cooling proportional band (P) Subsection 8.2.23 #103 #143 #183 Overlap/Dead band Subsection 8.2.27 Caution...

  • Page 51: Cascade Control

    6 Introduction of Functions -4LC User's Manual 6.7 Cascade control Cascade control 6.7.1 Cascade control Cascade control combines master channel control and slave channel control into one control loop. Cascade control is suitable for situations where there is a large time delay between the temperature near a heat source and the temperature of the object to be controlled.
  • Page 52 6 Introduction of Functions -4LC User's Manual 6.7 Cascade control Conditions for enabling cascade control • The master channel is separated from the slave channel, and the proper intermediate control quantity can be selected. • The response speed of the control target in the slave channel is sufficiently faster than the response speed of the control target in the master channel.

  • Page 53: Tuning During Cascade Control

    6 Introduction of Functions -4LC User's Manual 6.7 Cascade control 6.7.2 Tuning during cascade control Auto tuning and startup tuning are disabled while cascade control is being performed. Perform tuning in advance while cascade control is OFF, and then set PID constants regarded as approximate values.

  • Page 54: Sv Tracking Selection Function

    6 Introduction of Functions -4LC User's Manual 6.7 Cascade control 6.7.3 SV tracking selection function The SV tracking selection function makes the slave channel set value (SV) track the set value (value stored in the set value monitor buffer memory) just before changeover to cascade OFF when the cascade control function is changed from ON to OFF.

  • Page 55: Auto Tuning Function

    6 Introduction of Functions -4LC User's Manual 6.8 Auto Tuning Function Auto Tuning Function 6.8.1 AT (Auto tuning) The auto tuning function automatically measures, calculates and sets optimal PID constants in accordance with the set temperature. The auto tuning function is available in PID control and heating/cooling PID control. Write "1"...
  • Page 56 6 Introduction of Functions -4LC User's Manual 6.8 Auto Tuning Function Associated buffer memory BFM No. Description Reference CH1 CH2 CH3 CH4 Flag (b4 to b7 AT/ST abnormal end flag) Subsection 8.2.1 Event (b14 AT (auto tuning) being performed) Subsection 8.2.2 Measured value (PV) Subsection 8.2.3 #128 #168 Set value (SV)

  • Page 57: Conditions For Performing And Aborting At (Auto Tuning)

    6 Introduction of Functions -4LC User's Manual 6.8 Auto Tuning Function 6.8.2 Conditions for performing and aborting AT (auto tuning) 1. Conditions for performing AT (auto tuning) Auto tuning can be performed when all the following conditions are satisfied. • The control start/stop changeover set to "1 : Starts control". •...
  • Page 58 6 Introduction of Functions -4LC User's Manual 6.8 Auto Tuning Function Associated buffer memory BFM No. Description Reference CH1 CH2 CH3 CH4 Flag (b2 24V DC power supply error) (b4 to b7 AT/ST abnormal end flag) Subsection 8.2.1 (b8 Adjustment data error) (b9 Cold contact temperature compensation data error) (b10 A/D converted value error) Event...

  • Page 59: At (Auto Tuning) Bias

    6 Introduction of Functions -4LC User's Manual 6.8 Auto Tuning Function 6.8.3 AT (auto tuning) bias Set the auto tuning bias so that the measured value (PV) does not exceed the set value (SV) during auto tuning. The auto tuning function performs two-position control using the set value (SV), hunts the measured value (PV), then calculates and sets each PID constant.

  • Page 60: Startup Tuning Function

    6 Introduction of Functions -4LC User's Manual 6.9 Startup Tuning Function Startup Tuning Function 6.9.1 ST (startup tuning) The startup tuning function automatically measures, calculates and sets optimal PID constants based on the response characteristics of the control target when control is started or when the set value (SV) is changed. Startup tuning works as easy as auto tuning, and acquires PID constants in a short time at start of control without disturbing the controllability for a slow response control target.
  • Page 61 6 Introduction of Functions -4LC User's Manual 6.9 Startup Tuning Function Point • Before using the startup tuning function, confirm that all conditions for performing startup tuning and for aborting startup tuning (refer to Subsection 6.9.2) are satisfied. • Before starting startup tuning, set the output limiter upper limit to "100%", set the output limiter lower limit to "0%", and set the output change ratio limiter function to OFF so that optimal PID constants can be calculated by startup tuning.

  • Page 62: Conditions For Performing And Aborting St (Startup Tuning)

    6 Introduction of Functions -4LC User's Manual 6.9 Startup Tuning Function 6.9.2 Conditions for performing and aborting ST (startup tuning) 1. Conditions for performing ST (startup tuning) Startup tuning can be performed when all the following conditions are satisfied. • The ST execution command buffer memory is set to "1 : Performs ST". •...
  • Page 63 6 Introduction of Functions -4LC User's Manual 6.9 Startup Tuning Function • The output saturation time (Time when the output value has stopped at output limiter upper limit or output limiter lower limit) is short. • Hardware error is detected. - Sum check error caused by 24V DC power supply error or adjustment data error - Cold contact temperature compensation data error - A/D converter error...

  • Page 64: Auto/Manual Mode Changeover

    6 Introduction of Functions -4LC User's Manual 6.10 AUTO/MANUAL mode changeover 6.10 AUTO/MANUAL mode changeover 6.10.1 AUTO mode and MANUAL mode The mode can be changed over between "AUTO mode" and "MANUAL mode". The AUTO mode is selected when "K0" is written to the AUTO/MANUAL mode changeover buffer memory. The MANUAL mode is selected when "K1"...

  • Page 65: Balance-Less, Bump-Less Function

    6 Introduction of Functions -4LC User's Manual 6.10 AUTO/MANUAL mode changeover 6.10.2 Balance-less, bump-less function The balance-less, bump-less function prevents overload caused by drastic change in the control output value (MV) when the mode is changed over from AUTO mode to MANUAL mode (or from MANUAL mode to AUTO mode).

  • Page 66: Heater Disconnection Alarm Function (Hba)

    6 Introduction of Functions -4LC User's Manual 6.11 Heater Disconnection Alarm Function (HBA) 6.11 Heater Disconnection Alarm Function (HBA) 6.11.1 Heater disconnection alarm function The heater disconnection alarm function detects the current flowing in the load using a current detector (CT), it compares the detected value (heater current measured value) with the current value set for heater disconnection alarm, and issues an alarm when the measured value is more than or less than the current set value for the heater disconnection alarm.

  • Page 67: Number Of Times Of Heater Disconnection Alarm Delay

    6 Introduction of Functions -4LC User's Manual 6.11 Heater Disconnection Alarm Function (HBA) Associated buffer memory BFM No. Description Reference CH1 CH2 CH3 CH4 Event (b9 Heater disconnection alarm) Subsection 8.2.2 #24 Heater current measured value Subsection 8.2.7 #133 #173 Heater disconnection alarm set value Subsection 8.2.17 Number of times of heater disconnection alarm delay/ #235...

  • Page 68: Loop Breaking Alarm Function (Lba)

    6 Introduction of Functions -4LC User's Manual 6.12 Loop Breaking Alarm Function (LBA) 6.12 Loop Breaking Alarm Function (LBA) 6.12.1 Loop breaking alarm function The loop breaking alarm function starts to detect the variation of the measured value (PV), at every loop breaking alarm judgment time when the output becomes more than 100% (or the output limiter upper limit) or less than 0% (or the output limiter lower limit), then sets to ON the loop breaking alarm (b8) when judging that there is an abnormality in the control loop.
  • Page 69 6 Introduction of Functions -4LC User's Manual 6.12 Loop Breaking Alarm Function (LBA) Caution • The loop breaking alarm function judges abnormalities in the control loop, but cannot detect positions in which abnormalities occur. Check each part of the control system in turn. •...

  • Page 70: Loop Breaking Alarm Dead Zone (Lbd)

    6 Introduction of Functions -4LC User's Manual 6.12 Loop Breaking Alarm Function (LBA) 6.12.2 Loop breaking alarm dead zone (LBD) Set the loop breaking alarm judgement time. The loop breaking alarm function may issue alarms caused by disturbances (effect of another heat source, etc.) even if there is no abnormality in the control system.

  • Page 71: Alarm

    7 Alarm -4LC User's Manual 7.1 Alarm List Alarm The 4LC is equipped with 14 types of alarms. Four types of alarms (alarm 1 to alarm 4) are available in each channel in accordance with the application. Set the alarm type by writing the alarm mode (0 to 14) to the alarm mode setting buffer memories for alarms 1 to 4 (each channel).
  • Page 72 7 Alarm -4LC User's Manual 7.1 Alarm List Alarm Alarm type Description Setting range Reference mode When deviation (= Measured value (PV) - Set value (SV)) is less Lower limit deviation value than alarm set value, an alarm is issued. Subsection -Span to +Span alarm with re-wait...

  • Page 73: Alarm Functions

    7 Alarm -4LC User's Manual 7.2 Alarm Functions Alarm Functions The alarm functions issue an alarm when the measured value (PV) or deviation [Measured value (PV) - Set value (SV)] reaches the alarm set value. The alarm status can be checked in the status of bits for alarms 1 to 4 of the event buffer memory. For settings of alarm functions, refer to the following.

  • Page 74: Upper Limit Deviation Alarm

    7 Alarm -4LC User's Manual 7.2 Alarm Functions 7.2.3 Upper limit deviation alarm When the deviation (= Measured value (PV) - Set value (SV)) is more than the alarm set value, an alarm is issued. When the deviation is positive When the deviation is negative Measured value (PV) Measured value (PV)

  • Page 75: Range Alarm

    7 Alarm -4LC User's Manual 7.2 Alarm Functions 7.2.6 Range alarm When the absolute deviation (= Measured value (PV) - Set value (SV)) is less than the alarm set value, an alarm is issued. For example, if the alarm set value is "+10 C", an alarm is issued when the measured value (PV) is inside the range from "set value (SV) + 10 C"...

  • Page 76: Alarm Re-Wait Operation

    7 Alarm -4LC User's Manual 7.2 Alarm Functions 7.2.8 Alarm re-wait operation The alarm re-wait operation ignores the alarm status of the measured value (PV) when control is started, and disables the alarm function until the measured value (PV) enters the alarm region after the wait period has ended.

  • Page 77: Alarm Dead Zone Setting

    7 Alarm -4LC User's Manual 7.3 Alarm Dead Zone Setting Alarm Dead Zone Setting In BFM#233, set the dead zone of alarms 1 to 4. This setting is applied to all of alarms 1 to 4. When the measured value (PV) is near the alarm set value, the alarm status and the non-alarm status may be repeated by fluctuation in inputs.

  • Page 78: Number Of Times Of Alarm Delay

    7 Alarm -4LC User's Manual 7.4 Number of Times of Alarm Delay Number of Times of Alarm Delay In BFM#234, set the number of alarm delays. This setting is applied to all alarms 1 to 4. The alarm delay function keeps the non-alarm status until the number of input samples exceeds the number of alarm delays, after the deviation between the measured value (PV) and the set value (SV) reaches the alarm set value.

  • Page 79: Buffer Memory

    8 Buffer Memory -4LC User's Manual 8.1 Buffer Memory List Buffer Memory Each setting and alarm in the 4LC is written from or read to the PLC main unit through buffer memories. To read or write to the 4LC buffer memory, use FROM/TO instructions or specify buffer memory values directly.
  • Page 80 8 Buffer Memory -4LC User's Manual 8.1 Buffer Memory List BFM No. Initial Name Description/set range Remarks value CH1 CH2 CH3 CH4 PID control External output value monitor External output range lower limit to External output range Heating/cooling Heating external output value upper limit PID control monitor...
  • Page 81 8 Buffer Memory -4LC User's Manual 8.1 Buffer Memory List BFM No. Initial Name Description/set range Remarks value CH1 CH2 CH3 CH4 #109 #149 #189 Adjustment sensitivity (dead zone) setting 1 to 100 (0.1 to 10.0% of span) PID control Control output cycle setting #110 #150 #190 5 to 1000 (0.5 to 100.0 sec.)
  • Page 82 8 Buffer Memory -4LC User's Manual 8.1 Buffer Memory List BFM No. Initial Name Description/set range Remarks value CH1 CH2 CH3 CH4 0 to 3 : PID control #240 #241 Control mode switch 4 to 7 : Heating/cooling PID control 0 : Disable PID control SV tracking selection...

  • Page 83: Buffer Memory Details

    Set value backup error flag Turn the power ON again, and check for changes in the state. If no improvement is obtained, consult a Mitsubishi Electric distributor. Turns ON when CH1 AT (auto tuning) or ST (startup tuning) CH1 AT/ST abnormal end flag abnormally ends.

  • Page 84: Bfm#1 To 4] Event

    4LC. Turn the power ON again, and check for changes in the state. If no A/D converted value error improvement is obtained, consult a Mitsubishi Electric distributor. Alarm 1 Turns ON when an alarm 1 has occurred.

  • Page 85: Bfm#5 To 8] Measured Value (Pv)

    8 Buffer Memory -4LC User's Manual 8.2 Buffer Memory Details 8.2.3 [BFM#5 to 8] Measured value (PV) These buffer memories store the measured value (PV). The unit is " C", "0.1 C", " F", "0.1 F" or "mV" in accordance with the input type setting. The displayed measured value (PV) is as follows depending on the input type used.

  • Page 86: Bfm#9 To 12] Control Output Value (Mv) Monitor/Heating Control Output Value (Mv) Monitor

    8 Buffer Memory -4LC User's Manual 8.2 Buffer Memory Details 8.2.4 [BFM#9 to 12] Control output value (MV) monitor/ Heating control output value (MV) monitor In standard PID control, these buffer memories store the control output value (MV) after PID arithmetic operation or control output value (MV) in MANUAL mode.

  • Page 87: Bfm#17 To 20] Control Output Flag

    8 Buffer Memory -4LC User's Manual 8.2 Buffer Memory Details 8.2.6 [BFM#17 to 20] Control output flag Bit 0 and bit 8 indicate the ON/OFF status of the control output. However, the contents of control output vary depending on the setting of the control mode switch function and transistor output selection function.

  • Page 88: Bfm#21 To 24] Heater Current Measured Value

    8 Buffer Memory -4LC User's Manual 8.2 Buffer Memory Details 8.2.7 [BFM#21 to 24] Heater current measured value These buffer memories store the heater current measured value entered from the current detector (CT). BFM No. Initial Description Backup value CH1 CH2 CH3 CH4 #24 Display range : 0 to 1050 (0.0 to 105.0A) Caution •...

  • Page 89: Bfm#32 To 35] External Output Value/Heating External Output Value Monitor

    8 Buffer Memory -4LC User's Manual 8.2 Buffer Memory Details 8.2.11 [BFM#32 to 35] External output value/Heating external output value monitor When the control mode using external outputs is selected by the control mode switch function, these buffer memories store the control output processed within the output limit and scaled into the external output range. →...

  • Page 90: Bfm#44 To 47] Control Mode Monitor

    8 Buffer Memory -4LC User's Manual 8.2 Buffer Memory Details 8.2.14 [BFM#44 to 47] Control mode monitor These buffer memories indicate the current control mode and cascade control status. Bit 0 to bit 2 indicate the control mode, and bit 15 indicates the cascade control status. →...

  • Page 91: Bfm#48][Bfm#88][Bfm#128][Bfm#168] Set Value (Sv)

    8 Buffer Memory -4LC User's Manual 8.2 Buffer Memory Details 8.2.15 [BFM#48][BFM#88][BFM#128][BFM#168] Set value (SV) To these buffer memories, enter the set value (SV) used in the PID arithmetic operation and alarm function. The unit is " C", "0.1 C", " F", "0.1 F" or "mV" in accordance with the input type setting (BFM#208, BFM#214, BFM#220 and BFM#226).

  • Page 92: Bfm#53][Bfm#93][Bfm#133][Bfm#173] Heater Disconnection Alarm Set Value

    8 Buffer Memory -4LC User's Manual 8.2 Buffer Memory Details 8.2.17 [BFM#53][BFM#93][BFM#133][BFM#173] Heater disconnection alarm set value To these buffer memories, enter a value for recognizing heater disconnection or recognizing abnormal current while the output is OFF. • While the control output is ON When the heater current measured value is equivalent to or smaller than the heater disconnection alarm set value, a heater disconnection alarm is issued.

  • Page 93: Bfm#55][Bfm#95][Bfm#135][Bfm#175] Manual Output Set Value

    8 Buffer Memory -4LC User's Manual 8.2 Buffer Memory Details 8.2.19 [BFM#55][BFM#95][BFM#135][BFM#175] MANUAL output set value To these buffer memories, set the output ON ratio in MANUAL mode. Specify the ratio of the ON duration within the time (sec) specified by the control output cycle setting buffer memories.

  • Page 94: Bfm#57][Bfm#97][Bfm#137][Bfm#177] Operation Mode

    8 Buffer Memory -4LC User's Manual 8.2 Buffer Memory Details 8.2.21 [BFM#57][BFM#97][BFM#137][BFM#177] Operation mode These buffer memories specify the operation mode among "Monitor + Alarm + Control", "Monitor + Alarm", "Monitor" and "Not used". Write "K0" not to use the channel. Write "K1"...

  • Page 95: Bfm#58][Bfm#98][Bfm#138][Bfm#178] Proportional Band (P)/ Heating Proportional Band (P)

    8 Buffer Memory -4LC User's Manual 8.2 Buffer Memory Details 8.2.22 [BFM#58][BFM#98][BFM#138][BFM#178] Proportional band (P)/ Heating proportional band (P) To these buffer memories, set the proportional band (P) for performing standard PID control, or the proportional band (P) on the heating side for performing heating/cooling PID control. The proportional band is required to give the control output in proportion to the deviation (difference between the set value (SV) and the measured value (PV)).

  • Page 96: Bfm#60][Bfm#100][Bfm#140][Bfm#180] Integral Time (I)

    8 Buffer Memory -4LC User's Manual 8.2 Buffer Memory Details 8.2.24 [BFM#60][BFM#100][BFM#140][BFM#180] Integral time (I) To these buffer memories, set the integral time (I) for performing PID control. The integral operation changes the control output in proportion to the area made by the deviation size and deviation generation time.

  • Page 97: Bfm#62][Bfm#102][Bfm#142][Bfm#182] Control Response Parameter

    8 Buffer Memory -4LC User's Manual 8.2 Buffer Memory Details 8.2.26 [BFM#62][BFM#102][BFM#142][BFM#182] Control response parameter To these buffer memories, set the control response parameter. Select the response to changes in the set value (SV) in PID control among three steps (slow, medium and fast).

  • Page 98: Bfm#63][Bfm#103][Bfm#143][Bfm#183] Overlap/Dead Band

    8 Buffer Memory -4LC User's Manual 8.2 Buffer Memory Details 8.2.27 [BFM#63][BFM#103][BFM#143][BFM#183] Overlap/Dead band To these buffer memories, set the range of the overlap area or dead band for heating/cooling PID control. Enter a value in the range from -100 to -1 (negative value) to set the overlap area. Enter a value in the range from +1 to +100 (positive value) to set the dead band.

  • Page 99: Bfm#64][Bfm#104][Bfm#144][Bfm#184] Output Limiter Upper Limit/Heating Upper Output Limiter

    8 Buffer Memory -4LC User's Manual 8.2 Buffer Memory Details 8.2.28 [BFM#64][BFM#104][BFM#144][BFM#184] Output limiter upper limit/ Heating upper output limiter To these buffer memories, set the output limiter upper limit/heating output limiter upper limit for setting the upper limit of the control output value (MV). Set the upper limit of the output for standard PID control.

  • Page 100: Bfm#65][Bfm#105][Bfm#145][Bfm#185] Output Limiter Lower Limit

    8 Buffer Memory -4LC User's Manual 8.2 Buffer Memory Details 8.2.29 [BFM#65][BFM#105][BFM#145][BFM#185] Output limiter lower limit To these buffer memories, set the output limiter lower limit for setting the lower limit of the control output value (MV). → For an operation example of the output limiter lower limit, refer to Subsection 8.2.28. →...

  • Page 101: Bfm#67][Bfm#107][Bfm#147][Bfm#187] Output Change Ratio Limiter

    8 Buffer Memory -4LC User's Manual 8.2 Buffer Memory Details 8.2.31 [BFM#67][BFM#107][BFM#147][BFM#187] Output change ratio limiter The output change ratio limiter function limits changes in the control output value (MV) per unit time (1 sec). The preset output change ratio limits the control output. The output does not change drastically but is given in accordance with the preset inclination when the power is turned ON (and the output is outside the proportional band) or when the set value is changed (significantly).

  • Page 102: Bfm#68][Bfm#108][Bfm#148][Bfm#188] Sensor Correction Value Setting

    8 Buffer Memory -4LC User's Manual 8.2 Buffer Memory Details 8.2.32 [BFM#68][BFM#108][BFM#148][BFM#188] Sensor correction value setting To these buffer memories, enter the sensor correction value for correcting the dispersion among sensors or correcting differences in the measured value (PV) from other instruments. The actual input value is added to the sensor correction value, and then stored in the measured value (PV) buffer memory.

  • Page 103: Bfm#69][Bfm#109][Bfm#149][Bfm#189] Adjustment Sensitivity (Dead Zone) Setting

    8 Buffer Memory -4LC User's Manual 8.2 Buffer Memory Details 8.2.33 [BFM#69][BFM#109][BFM#149][BFM#189] Adjustment sensitivity (dead zone) setting To these buffer memories, enter the adjustment sensitivity (dead zone) to prevent chattering of the control output (MV) around the set value (SV) during two-position control. The value entered to these buffer memories is divided into two and distributed upward and downward around the set value (SV).

  • Page 104: Bfm#70][Bfm#110][Bfm#150][Bfm#190] Control Output Cycle Setting/Heating Control Output Period Setting

    8 Buffer Memory -4LC User's Manual 8.2 Buffer Memory Details 8.2.34 [BFM#70][BFM#110][BFM#150][BFM#190] Control output cycle setting/ Heating control output period setting To these buffer memories, enter the control output (MV) cycle. For heating/cooling PID control, enter the control output (MV) cycle on the heating side. Set the time in which the control output (MV) turns ON and OFF.

  • Page 105: Bfm#72][Bfm#112][Bfm#152][Bfm#192] Primary Delay Digital Filter Setting

    8 Buffer Memory -4LC User's Manual 8.2 Buffer Memory Details 8.2.36 [BFM#72][BFM#112][BFM#152][BFM#192] Primary delay digital filter setting To these buffer memories, enter the primary delay digital filter for reducing fluctuations caused by noise in the measured value (MV). The effect of noise is mitigated by setting the time constant of the digital filter here in accordance with the control target characteristics and noise level.

  • Page 106: Bfm#73][Bfm#113][Bfm#153][Bfm#193] Setting Change Ratio Limiter

    8 Buffer Memory -4LC User's Manual 8.2 Buffer Memory Details 8.2.37 [BFM#73][BFM#113][BFM#153][BFM#193] Setting change ratio limiter When the set value (SV) is changed, the setting change ratio limiter function changes the difference between the former set value (SV) and the new set value (SV) gradually. Use this function to avoid drastic change in the set value (SV).

  • Page 107: Bfm#74][Bfm#114][Bfm#154][Bfm#194] At (Auto Tuning) Bias

    8 Buffer Memory -4LC User's Manual 8.2 Buffer Memory Details 8.2.38 [BFM#74][BFM#114][BFM#154][BFM#194] AT (auto tuning) bias To these buffer memories, enter the AT bias to prevent the measured value (PV) from exceeding the set value (SV) during auto tuning. The auto tuning function performs two-position control using the set value (SV), hunts the measured value (PV), then calculates and sets each PID constant.

  • Page 108: Bfm#75][Bfm#115][Bfm#155][Bfm#195] Normal/Reverse Operation Selection

    8 Buffer Memory -4LC User's Manual 8.2 Buffer Memory Details 8.2.39 [BFM#75][BFM#115][BFM#155][BFM#195] Normal/reverse operation selection To these buffer memories, set whether normal operation or reverse operation is performed in standard PID control. Enter "K0" to specify normal operation. Enter "K1" to specify reverse operation. BFM No.

  • Page 109: Bfm#76][Bfm#116][Bfm#156][Bfm#196] Setting Limiter Upper Limit

    8 Buffer Memory -4LC User's Manual 8.2 Buffer Memory Details 8.2.40 [BFM#76][BFM#116][BFM#156][BFM#196] Setting limiter upper limit To these buffer memories, set the setting limiter upper limit for setting the upper limit of the set value (SV). → For details on the set value (SV), refer to Subsection 8.2.15. →...

  • Page 110: Bfm#78][Bfm#118][Bfm#158][Bfm#198] Loop Breaking Alarm Judgement Time

    8 Buffer Memory -4LC User's Manual 8.2 Buffer Memory Details 8.2.42 [BFM#78][BFM#118][BFM#158][BFM#198] Loop breaking alarm judgement time To these buffer memories, enter the loop breaking alarm judgment time. The loop breaking alarm function starts to detect the variation of the measured value (PV), at every loop breaking alarm judgment time when the output becomes more than 100% (or the output limiter upper limit) or less than 0% (or the output limiter lower limit), then sets to ON the loop breaking alarm when judging that there is an abnormality in the control loop.

  • Page 111: Bfm#79][Bfm#119][Bfm#159][Bfm#199] Loop Breaking Alarm Dead Zone

    8 Buffer Memory -4LC User's Manual 8.2 Buffer Memory Details 8.2.43 [BFM#79][BFM#119][BFM#159][BFM#199] Loop breaking alarm dead zone Set the loop breaking alarm judgement time. The loop breaking alarm function may issue alarms caused by disturbances (effect of another heat source, etc.) even if there is no abnormality in the control system.

  • Page 112: Bfm#80][Bfm#120][Bfm#160][Bfm#200] Micro Voltage Input Scaling Upper Limit

    8 Buffer Memory -4LC User's Manual 8.2 Buffer Memory Details 8.2.44 [BFM#80][BFM#120][BFM#160][BFM#200] Micro voltage input scaling upper limit To these buffer memories, set the micro voltage input scaling upper limit for setting the upper limit of the display range for the micro voltage input. →...

  • Page 113: Bfm#84][Bfm#124][Bfm#164][Bfm#204] External Output Range Upper Limit

    8 Buffer Memory -4LC User's Manual 8.2 Buffer Memory Details 8.2.48 [BFM#84][BFM#124][BFM#164][BFM#204] External output range upper limit To these buffer memories, set the external output range upper limit for setting the upper limit of the external output. → For details on the external output range lower limit, refer to Subsection 8.2.49. BFM No.

  • Page 114: Bfm#86][Bfm#126][Bfm#166][Bfm#206] Transistor Output Selection

    8 Buffer Memory -4LC User's Manual 8.2 Buffer Memory Details 8.2.50 [BFM#86][BFM#126][BFM#166][BFM#206] Transistor output selection To these buffer memories, set the function of transistor outputs built into the 4LC. Available transistor output functions vary depending on the control mode setting. →...

  • Page 115: Bfm#87][Bfm#127][Bfm#167][Bfm#207] St (Startup Tuning) Execution Command

    8 Buffer Memory -4LC User's Manual 8.2 Buffer Memory Details 8.2.51 [BFM#87][BFM#127][BFM#167][BFM#207] ST (startup tuning) execution command To these buffer memories, set stop or execution of startup tuning. Write "K0" to stop startup tuning. Write "K1" to perform startup tuning. →...

  • Page 116: Bfm#208][Bfm#214][Bfm#220][Bfm#226] Input Type

    8 Buffer Memory -4LC User's Manual 8.2 Buffer Memory Details 8.2.52 [BFM#208][BFM#214][BFM#220][BFM#226] Input type To these buffer memories, set the input type. BFM No. Initial Description Backup value CH1 CH2 CH3 CH4 #208 #214 #220 #226 Input type (Refer to the following) These buffer memories can be written only while control is stopped.

  • Page 117: Bfm#209 To #212][Bfm#215 To #218][Bfm#221 To #224][Bfm#227 To #230] Alarm Mode Setting 1 To 4

    8 Buffer Memory -4LC User's Manual 8.2 Buffer Memory Details 8.2.53 [BFM#209 to #212][BFM#215 to #218][BFM#221 to #224][BFM#227 to #230] Alarm mode setting 1 to 4 The 4LC is equipped with 14 types of alarms. Four types of alarms (alarm 1 to alarm 4) are available in each channel in accordance with the application.

  • Page 118: Bfm#232] Cooling Method Setting

    8 Buffer Memory -4LC User's Manual 8.2 Buffer Memory Details Alarm Alarm type Description mode When absolute deviation (= Measured value (PV) - Set value (SV)) is more than Upper/lower limit deviation value alarm set value, an alarm is issued. alarm with re-wait However, when control is started and when set value is changed the measured value is ignored.

  • Page 119: Bfm#233] Alarm Dead Band Setting

    8 Buffer Memory -4LC User's Manual 8.2 Buffer Memory Details 8.2.55 [BFM#233] Alarm dead band setting To these buffer memories, set the dead zone for alarms 1 to 4. The setting is applied to alarms 1 to 4 in all channels. When the measured value (PV) is around the alarm set value, the alarm status and non-alarm status may be repeated due to input fluctuations.

  • Page 120: Bfm#234] Alarm Delay Count

    8 Buffer Memory -4LC User's Manual 8.2 Buffer Memory Details Example of operation 3 (Upper/lower limit deviation) Measured value (PV) Measured value (PV) Alarm set value Dead zone Set value (SV) Dead zone Alarm set value Time Alarm status Non-alarm status Alarm status Caution Handling numbers containing decimal places.

  • Page 121: Bfm#235] Number Of Times Of Heater Disconnection Alarm Delay/Number Of Times Of Current Error Detection When Output Is Off Delay

    8 Buffer Memory -4LC User's Manual 8.2 Buffer Memory Details 8.2.57 [BFM#235] Number of times of heater disconnection alarm delay/ Number of times of current error detection when output is OFF delay To this buffer memory, set the number of times of delay for detecting heater disconnection or detecting current abnormality while the output is OFF.

  • Page 122: Bfm#237] Temperature Rise Completion Soak Time

    8 Buffer Memory -4LC User's Manual 8.2 Buffer Memory Details 8.2.59 [BFM#237] Temperature rise completion soak time To this buffer memory, set the temperature rise completion soak time. The setting is applied to all channels. When the measured value (PV) remains in the temperature rise completion range until the temperature rise completion soak time is finished, the temperature rise completion flag (b15) of the event buffer memory turns →...

  • Page 123: Bfm#238] Ct Monitor Method Switch

    8 Buffer Memory -4LC User's Manual 8.2 Buffer Memory Details 8.2.60 [BFM#238] CT monitor method switch To this buffer memory, enter the heater current measured value display method. The setting is applied to all channels. The control output (MV) turns ON and OFF repeatedly while control is being performed, and the current at control output ON and the current at control output OFF are displayed alternately.

  • Page 124: Bfm#240, #241] Control Mode Switch

    8 Buffer Memory -4LC User's Manual 8.2 Buffer Memory Details 8.2.62 [BFM#240, #241] Control mode switch To these buffer memories, set the control type (standard PID control, two-position control, manual control, cascade control or heating/cooling control) and used inputs/outputs (external or internal) for each control group.

  • Page 125: Bfm#242, #243] Sv Tracking Selection

    8 Buffer Memory -4LC User's Manual 8.2 Buffer Memory Details 8.2.63 [BFM#242, #243] SV tracking selection The SV tracking selection function makes the slave channel set value (SV) track the set value (value stored in the set value monitor buffer memory) just before changeover to cascade OFF when the cascade control function is changed from ON to OFF.

  • Page 126: Bfm#244, #245] Cascade On/Off

    8 Buffer Memory -4LC User's Manual 8.2 Buffer Memory Details 8.2.64 [BFM#244, #245] Cascade ON/OFF Using these buffer memories, turn ON or OFF cascade control. Write "K0" to turn OFF cascade control. Write "K1" to turn ON cascade control. When cascade control is changed over from OFF to ON, the control output from the master channel is changed over without bump.

  • Page 127: Bfm#248, #249] Cascade Bias

    8 Buffer Memory -4LC User's Manual 8.2 Buffer Memory Details 8.2.66 [BFM#248, #249] Cascade bias To these buffer memories, set the cascade bias added to the control output (MV) from the master channel during cascade control. Control group 1 (GR1) : The setting is applied to CH1 and CH2. Control group 2 (GR2) : The setting is applied to CH3 and CH4.

  • Page 128: Bfm#252] Set Value Range Error Address

    8 Buffer Memory -4LC User's Manual 8.2 Buffer Memory Details 8.2.68 [BFM#252] Set value range error address When a value written to each buffer memory is outside the setting range, the set value range error flag (b1) turns ON, and this buffer memory BFM#252 stores the buffer memory number where the error has occurred. The setting is applied to all channels.

  • Page 129: Bfm#254] Set Value Backup Command

    8 Buffer Memory -4LC User's Manual 8.2 Buffer Memory Details 8.2.70 [BFM#254] Set value backup command Back up the set values using this buffer memory. Write "K1" to write the set values of the backup target buffer memories to the EEPROM built into the 4LC. The setting is applied to all channels.

  • Page 130: Bfm#255] Initialization Command

    8 Buffer Memory -4LC User's Manual 8.2 Buffer Memory Details 8.2.71 [BFM#255] Initialization command Initialize the set values using this buffer memory. The initialization range varies depending on the set value. Write "K1" to initialize all buffer memories. Write "K2" to initialize buffer memories #48 to #207, #232 and #242 to #247 in accordance with the input type (in the case of internal input) and control mode.

  • Page 131: Program Examples

    • Do not disassemble or modify the PLC. Doing so may cause fire, equipment failures, or malfunctions. For repair, contact your local Mitsubishi Electric distributor. • Turn off the power to the PLC before attaching or detaching the following devices.

  • Page 132: Reading/Writing Buffer Memory

    9 Program Examples -4LC User's Manual 9.1 Reading/Writing Buffer Memory Reading/Writing Buffer Memory 9.1.1 Assigned unit number 1. Assigned unit number The unit number for the 4LC is automatically assigned No.0 to No.7 starting from the special function unit/ block closest to the PLC main unit. •...
  • Page 133 9 Program Examples -4LC User's Manual 9.1 Reading/Writing Buffer Memory b) Writing numeric values to the buffer memory In the program below, "K32,000" is written to the buffer memory (BFM#25) in the unit No. 1. Write command FNC 12 K32,000 U1\G25 Transfer source Buffer memory No.
  • Page 134 9 Program Examples -4LC User's Manual 9.1 Reading/Writing Buffer Memory 2. How to read and write the bit information such as flag and event 1) Direct specification of buffer memory Specify the buffer memory directly as the source in applied instructions, and read or write the contents. U \G is substituted with a number Unit No.
  • Page 135 9 Program Examples -4LC User's Manual 9.1 Reading/Writing Buffer Memory c) Writing the bit information of auxiliary relays to the buffer memory In the program below, the ON/OFF status of auxiliary relays (M20 to M35) is written to the buffer memory (BFM#518) in the unit No.
  • Page 136 9 Program Examples -4LC User's Manual 9.1 Reading/Writing Buffer Memory b) Reading and transferring the bit information to data registers In the program below, the contents of the buffer memory (BFM#0) in the unit No. 1 are read and transferred to a data register (D200). The read bit information is used in bit specification of word devices.

  • Page 137: Example Of A Program For Pid Control

    9 Program Examples -4LC User's Manual 9.2 Example of a Program for PID Control Example of a Program for PID Control This section provides an example of a program for PID control. 9.2.1 System configuration The system configuration shown below explains the example program. CH2 Measured value (PV) CH1 Sensor CH2 Sensor...

  • Page 138: Device Assignments

    9 Program Examples -4LC User's Manual 9.2 Example of a Program for PID Control 9.2.3 Device assignments Device assignments of the example program are assigned as follows. Device No. Contents of operation X000 When X000 is turned on, parameters are initialized in the buffer memory. X001 Initializes all data.

  • Page 139: Sequence Program

    9 Program Examples -4LC User's Manual 9.2 Example of a Program for PID Control 9.2.4 Sequence program The sequence program for the example program with the FX -4LC as unit No. 0 is shown below. Change unit No.0 to match the actual system configuration to be used. The FROM/TO instructions are used for read/write of buffer memory.
  • Page 140 9 Program Examples -4LC User's Manual 9.2 Example of a Program for PID Control From previous page From previous page M100 Alarm mode setting 1 (CH1): K209 Upper limit deviation alarm with re-wait Initialization completed Alarm mode setting 1 (CH2): K215 flag Upper limit deviation alarm with re-wait...
  • Page 141 9 Program Examples -4LC User's Manual 9.2 Example of a Program for PID Control From previous page From previous page Initializes all data. When X001 is set to ON, all X001 data is initialized. K255 (When initialization is not Performs initialization necessary, this line can be omitted.) X002...

  • Page 142: Example Of A Program For Heating/Cooling Pid Control

    9 Program Examples -4LC User's Manual 9.3 Example of a Program for Heating/Cooling PID Control Example of a Program for Heating/Cooling PID Control This section provides an example of a program for heating/cooling PID control. 9.3.1 System configuration The system configuration shown below explains the example program. CH1 Measured value (PV) CH1 Sensor (Type K thermocouple)

  • Page 143: Device Assignments

    9 Program Examples -4LC User's Manual 9.3 Example of a Program for Heating/Cooling PID Control 9.3.3 Device assignments Device assignments of the example program are assigned as follows. Device No. Contents of operation X000 When X000 is turned on, parameters are initialized in the buffer memory. X001 Initializes all data.

  • Page 144: Sequence Program

    9 Program Examples -4LC User's Manual 9.3 Example of a Program for Heating/Cooling PID Control 9.3.4 Sequence program The sequence program for the example program with the FX -4LC as unit No. 0 is shown below. Change unit No.0 to match the actual system configuration to be used. The FROM/TO instructions are used for read/write of buffer memory.
  • Page 145 9 Program Examples -4LC User's Manual 9.3 Example of a Program for Heating/Cooling PID Control From previous page M100 Cooling method setting K232 Air cooling type (initial value) Initialization completed flag Temperature rise completion range: K236 CT monitor method: K238 ON current/OFF current (initial value) CT ratio setting: K239...
  • Page 146 9 Program Examples -4LC User's Manual 9.3 Example of a Program for Heating/Cooling PID Control From previous page From previous page Initializes all data. When X001 is set to ON, all X001 data is initialized. K255 (When initialization is not Performs initialization necessary, this line can be omitted.)

  • Page 147: Troubleshooting

    • Do not disassemble or modify the PLC. Doing so may cause fire, equipment failures, or malfunctions. For repair, contact your local Mitsubishi Electric distributor. • Turn off the power to the PLC before attaching or detaching the following devices.

  • Page 148: Troubleshooting Procedure

    Set value backup error flag Turn the power ON again, and check for changes in the state. If no improvement is obtained, consult a Mitsubishi Electric distributor. Turns ON when CH1 AT (auto tuning) or ST (startup tuning) abnormally CH1 AT/ST abnormal end flag ends.

  • Page 149: Diagnostics On The Plc Main Unit

    If the power is not OFF, check the power supply and the power supply occurred. route. • The power supply is OFF. If power is being supplied correctly, consult a Mitsubishi Electric • Incorrect external wiring. distributor. • Power of the specified voltage is not •...

  • Page 150: Error (Err) Led [On/Flashing/Off]

    Fit a noise filter onto the power supply line. 3) If the ERROR (ERR) LED does not go out even after measures in 1) and 2) are adopted, consult a Mitsubishi Electric distributor. One of the following errors has occurred on...

  • Page 151: Appendix A: Version Information

    Appendix A: Version Information -4LC User's Manual Appendix A-1 Version Information Appendix A: Version Information Appendix A-1 Version Information Appendix A-1-1 Version check method The 4LC version is shown as "S/N" on the label attached to the right side of the module as seen from the front.
  • Page 152 Appendix A: Version Information -4LC User's Manual Appendix A-1 Version Information MEMO...

  • Page 153: Warranty

    -4LC User's Manual Warranty Warranty Please confirm the following product warranty details before using this product. 1. Gratis Warranty Term and Gratis Warranty Range 2. Onerous repair term after discontinuation of production If any faults or defects (hereinafter "Failure") found to be the responsibility of Mitsubishi occurs during use of the Mitsubishi shall accept onerous product repairs for product within the gratis warranty term, the product shall be...

  • Page 154: Revised History

    -4LC User's Manual Revised History Revised History Date Revision Description 1/2010 First Edition 5/2010 Errors are corrected.
  • Page 155 -4LC USER'S MANUAL HEAD OFFICE: TOKYO BUILDING, 2-7-3 MARUNOUCHI, CHYODA-KU, TOKYO 100-8310, JAPAN HIMEJI WORKS: 840, CHIYODA CHO, HIMEJI, JAPAN FX3U-4LC-U-E MODEL 09R625 MODEL CODE JY997D39101B Effective May 2010 (MEE) Specifications are subject to change without notice.
  • Page 156 Phone: +370 (0)5 / 232 3101 Fax: +370 (0)5 / 232 2980 MITSUBISHI ELECTRIC Mitsubishi Electric Europe B.V. /// FA - European Business Group /// Gothaer Straße 8 /// D-40880 Ratingen /// Germany Tel.: +49(0)2102-4860 /// Fax: +49(0)2102-4861120 /// info@mitsubishi-automation.com /// www.mitsubishi-automation.com FACTORY AUTOMATION...

Table of Contents