Mitsubishi FX3U-232-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-37
6.2 Important Points in Computer Link............................................................................................ D-38
6.2.1 Operations of PLC caused by data transfer .............................................................................. D-38
6.3 How to Understand Control Procedure ..................................................................................... D-39
6.4 Basic Formats of Dedicated Protocol........................................................................................ D-39
6.4.1 Control procedure format 1........................................................................................................ D-40
6.4.2 Control procedure format 4........................................................................................................ D-41
6.4.3 Contents of set items in each control procedure (protocol) ....................................................... D-42
6.4.4 Time-out time setting ................................................................................................................. D-44
6.5 Transfer Sequence Time Chart and Communication Time....................................................... D-45
6.5.1 When computer reads data from PLC ....................................................................................... D-45
6.5.2 When computer writes data to PLC........................................................................................... D-45
6.5.3 Transfer time in transfer sequence............................................................................................ D-46
6.6 Transfer Data in Character Area ............................................................................................... D-47
6.6.1 When bit device memory is read or written ............................................................................... D-47
6.6.2 When word device memory is read or written ........................................................................... D-48
7. Commands
7.1 BR Command [Reads Device Memory in 1-Bit Units]............................................................... D-50
7.2 WR Command [Reads Device Memory in 1-Word Units] ......................................................... D-51
7.3 QR Command [Reads Device Memory in 1-Word Units] .......................................................... D-53
7.4 BW Command [Writes Device Memory in 1-Bit Units] .............................................................. D-55
7.5 WW Command [Writes Device Memory in 1-Word Units]......................................................... D-56
7.6 QW Command [Writes Device Memory in 1-Word Units] ......................................................... D-58
7.7 BT Command [Tests Device Memory in 1-Bit Units (by Writing Arbitrarily)] ............................. D-60
7.8 WT Command [Tests Device Memory in 1-Word Units (by Writing Arbitrarily)]........................ D-61
7.9 QT Command [Tests Device Memory in 1-Word Units (by Writing Arbitrarily)] ........................ D-63
7.10 RR/RS Command [Remotely Sets PLC to RUN/STOP Mode] ............................................... D-64
7.10.1 Contents of remote control to set RUN or STOP mode........................................................... D-64
7.10.2 Condition validating remote control to set RUN or STOP mode.............................................. D-64
7.10.3 Remote control specification method and specification examples .......................................... D-65
7.11 PC Command [Reads PLC Model Name]............................................................................... D-66
7.11.1 PLC model name (CPU) and read contents ............................................................................ D-66
7.11.2 Control procedure specification method and specification example........................................ D-66
7.12 GW Command [Offers Global Function] ................................................................................. D-67
7.12.1 Contents of control .................................................................................................................. D-67
7.12.2 Global function control procedure specification method and specification example ............... D-67
7.13 On-demand Function .............................................................................................................. D-68
7.13.1 Special data registers and special auxiliary relays used in on-demand function..................... D-68
7.13.2 Control procedures in on-demand function ............................................................................. D-70
7.13.3 On-demand function specification method and specification examples .................................. D-72
7.14 TT Command [Loop-back Test] .............................................................................................. D-75
8. Troubleshooting
8.1 Checking FX PLC Version Applicability .................................................................................... D-76
8.2 Checking Communication Status Based on LED Indication ..................................................... D-76
8.3 Checking Installation and Wiring............................................................................................... D-76
8.4 Checking Sequence Program ................................................................................................... D-77
8.5 Checking Error Codes............................................................................................................... D-78
8.5.1 Error codes when NAK is sent................................................................................................... D-78
8.5.2 Error codes in PLC .................................................................................................................... D-79
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Table of Contents
D-37
D-49
D-76