Modbus Standard Commands; Modbus Standard Commands Support List - Mitsubishi FX3U Series User Manual

FX Series Programmable Controllers
3U
User's Manual - MODBUS Serial Communication Edition
7.

MODBUS Standard Commands

The following chapter explains in detail MODBUS Communication. For standard use of the FX
Serial function please refer to Chapter 8 (Master Specification) or Chapter 9 (Slave Specification).
7.1

MODBUS Standard Commands Support List

The following table indicates a list of the MODBUS standard functions supported by the FX-Series MODBUS
Communication ADP.
Command Subcommand
Code
0x01
0x02
0x03
0x04
0x05
0x06
0x07
0x00
0x01
0x02
0x08
Diagnosis
0x03
0x04
0x0A
0x0B
Command Name
Code
Read Coils
Read Discrete
Inputs
Read Holding
Registers
Read Input
Registers
Write Single Coil
Write Single
Register
Read Exception
Status
Return Query Data
Restart
Communication
Option
Return Diagnostic
Register
Change ASCII Input
Delimiter
Force Listen Only
Mode
Clear Counters and
Diagnostic Register
Return Bus
Message Count
7.1 MODBUS Standard Commands Support List
Accessible
Details Devices per
Message
Read binary (R/W) 1 to 2000
devices points
Read binary (RO) 1 to 2000
devices points
Read 16 bit (R/W) 1 to 125
register points
Read 16 bit (RO) 1 to 125
register points
Write single binary
1 point
device
Write single 16 bit
1 point
register device
Read 1 byte of
vendor specified -
data
Loop back
-
function
Restart
communication/
Remote -
Communication
Reset
Read 16 bit
register of vendor -
specified data
Change ASCII
mode End of
-
Message
character
Switch slave to
-
Listen Only Mode
Clear all counters
and the diagnostic -
registers
Read number of
detected -
messages
7 MODBUS Standard Commands
MODBUS
3U
Broadcast Reference
✘
Section 7.4
✘ Section 7.5
✘
Section 7.6
✘
Section 7.7
✔ Section 7.8
✔
Section 7.9
✘ Section 7.10
Subsection
✘
7.11.1
Subsection
✔
7.11.2
Subsection
✘
7.11.3
Subsection
✔
7.11.4
Subsection
✔
7.11.5
Subsection
✔
7.11.6
Subsection
✘
7.11.7
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