Mitsubishi FX3U-USB-BD User Manual page 14

FX Series PLC User's Manual - Data Communication Edition
6. Control Procedures and Setting Methods
6.1 Data Flow by Link...................................................................................................................... D-42
6.2 Important Points in Computer Link............................................................................................ D-43
6.2.1 Operations of PLC caused by data transfer .............................................................................. D-43
6.3 How to Understand Control Procedure ..................................................................................... D-44
6.4 Basic Formats of Dedicated Protocol........................................................................................ D-44
6.4.1 Control procedure format 1........................................................................................................ D-45
6.4.2 Control procedure format 4........................................................................................................ D-46
6.4.3 Contents of set items in each control procedure (protocol) ....................................................... D-47
6.4.4 Time-out time setting ................................................................................................................. D-49
6.5 Transfer Sequence Time Chart and Communication Time....................................................... D-50
6.5.1 When computer reads data from PLC ....................................................................................... D-50
6.5.2 When computer writes data to PLC........................................................................................... D-50
6.5.3 Transfer time in transfer sequence............................................................................................ D-51
6.6 Transfer Data in Character Area ............................................................................................... D-52
6.6.1 When bit device memory is read or written ............................................................................... D-52
6.6.2 When word device memory is read or written ........................................................................... D-53
7. Commands
7.1 BR Command [Reads Device Memory in 1-Bit Units]............................................................... D-55
7.2 WR Command [Reads Device Memory in 1-Word Units] ......................................................... D-56
7.3 QR Command [Reads Device Memory in 1-Word Units] .......................................................... D-58
7.4 BW Command [Writes Device Memory in 1-Bit Units] .............................................................. D-60
7.5 WW Command [Writes Device Memory in 1-Word Units]......................................................... D-61
7.6 QW Command [Writes Device Memory in 1-Word Units] ......................................................... D-63
7.7 BT Command [Tests Device Memory in 1-Bit Units (by Writing Arbitrarily)] ............................. D-65
7.8 WT Command [Tests Device Memory in 1-Word Units (by Writing Arbitrarily)]........................ D-66
7.9 QT Command [Tests Device Memory in 1-Word Units (by Writing Arbitrarily)] ........................ D-68
7.10 RR/RS Command [Remotely Sets PLC to RUN/STOP Mode] ............................................... D-69
7.10.1 Contents of remote control to set RUN or STOP mode........................................................... D-69
7.10.2 Condition validating remote control to set RUN or STOP mode.............................................. D-69
7.10.3 Remote control specification method and specification examples .......................................... D-70
7.11 PC Command [Reads PLC Model Name]............................................................................... D-71
7.11.1 PLC model name (CPU) and read contents ............................................................................ D-71
7.11.2 Control procedure specification method and specification example........................................ D-71
7.12 GW Command [Offers Global Function] ................................................................................. D-73
7.12.1 Contents of control .................................................................................................................. D-73
7.12.2 Global function control procedure specification method and specification example ............... D-73
7.13 On-demand Function .............................................................................................................. D-74
7.13.1 Special data registers and special auxiliary relays used in on-demand function..................... D-74
7.13.2 Control procedures in on-demand function ............................................................................. D-76
7.13.3 On-demand function specification method and specification examples .................................. D-78
7.14 TT Command [Loop-back Test] .............................................................................................. D-81
8. Troubleshooting
8.1 Checking FX PLC Version Applicability .................................................................................... D-82
8.2 Checking Communication Status Based on LED Indication ..................................................... D-82
8.3 Checking Installation and Wiring............................................................................................... D-82
8.4 Checking Sequence Program ................................................................................................... D-83
8.5 Checking Error Codes............................................................................................................... D-84
8.5.1 Error codes when NAK is sent................................................................................................... D-84
8.5.2 Error codes in PLC .................................................................................................................... D-85
10
Table of Contents
D-42
D-54
D-82