Mitsubishi FX3U Series User Manual page 8

FX Series Programmable Controllers
3U
User's Manual - MODBUS Serial Communication Edition
6. Related Devices and Communication Status
6.1 Special Data Registers.................................................................................................................. 32
6.2 Communication setting for MODBUS............................................................................................ 37
6.3 Special Auxiliary Relays................................................................................................................ 38
6.4 Communication status................................................................................................................... 40
7. MODBUS Standard Commands
7.1 MODBUS Standard Commands Support List ............................................................................... 41
7.2 Frame Specifications..................................................................................................................... 43
7.2.1 Frame mode .................................................................................................................................. 44
7.3 Protocol Data Unit Formats by Commands................................................................................... 48
7.4 Read Coils (Command Code: 0x01) ............................................................................................. 50
7.5 Read Discrete Inputs (Command Code: 0x02) ............................................................................. 51
7.6 Read Holding Registers (Command Code: 0x03)......................................................................... 52
7.7 Read Input Registers (Command Code: 0x04) ............................................................................. 53
7.8 Write Single Coil (Command Code: 0x05) .................................................................................... 54
7.9 Write Single Register (Command Code: 0x06) ............................................................................. 55
7.10 Read Exception Status (Command Code: 0x07) ........................................................................ 56
7.11 Diagnostics (Command Code: 0x08) .......................................................................................... 57
7.11.1 Return query data (sub-comand code: 0x00) .............................................................................. 57
7.11.2 Restart communications option (sub-command code: 0x01) ...................................................... 58
7.11.3 Return diagnostic register (sub-command code: 0x02)............................................................... 59
7.11.4 Change ASCII input delimiter (sub-command code: 0x03) ......................................................... 60
7.11.5 Force listen only mode (sub-command code: 0x04).................................................................... 61
7.11.6 Clear counters and diagnostic register (sub-command code: 0x0A)........................................... 62
7.11.7 Return bus message count (sub-command code: 0x0B) ............................................................ 63
7.11.8 Return bus communication error count (sub-command code: 0x0C) .......................................... 64
7.11.9 Return bus exception error count (sub-command code: 0x0D)................................................... 65
7.11.10 Return slave message count (sub-command code: 0x0E)........................................................ 66
7.11.11 Return slave no response count (sub-command code: 0x0F)................................................... 67
7.11.12 Return slave NAK count (sub-command code: 0x10) ............................................................... 68
7.11.13 Return slave busy count (sub-command code: 0x11) ............................................................... 69
7.11.14 Return bus character overrun count (sub-command code: 0x12) ............................................. 70
7.12 Get Communications Event Counter (Command Code: 0x0B)................................................... 71
7.13 Get Communications Event Log (Command Code: 0x0C) ......................................................... 72
7.14 Write Multiple Coils (Command Code: 0x0F).............................................................................. 73
7.15 Write Multiple Registers (Command Code: 0x10)....................................................................... 74
7.16 Report Slave ID (Command Code: 0x11) ................................................................................... 75
7.17 Mask Write Register (Command Code: 0x16) ............................................................................ 76
7.18 Read/Write Multiple Registers (Command Code: 0x17) ............................................................. 77
8. Master Specification
8.1 MODBUS Master Command List .................................................................................................. 78
8.2 FNC 276 - MODBUS Read/Write Instruction ................................................................................ 79
8.2.1 Outline ........................................................................................................................................... 79
8.2.2 Explanation of function and operation ........................................................................................... 79
8.3 ADPRW Command Parameters.................................................................................................... 80
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Table of Contents
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