Slave Specification; Modbus Slave Command Code List - Mitsubishi FX3U Series User Manual

FX Series Programmable Controllers
3U
User's Manual - MODBUS Serial Communication Edition
9.

Slave Specification

This chapter explains the configuration of the slave for MODBUS Serial Communication.
9.1

MODBUS Slave Command Code List

Command Code
0x01
0x02
0x03
0x04
0x05
0x06
0x07
0x08
Diagnosis
84
Subcommand
Command Name
Code
Read Coils
Read Discrete Inputs
Read Holding Registers
Read Input Registers
Write Single Coil
Write Single Register
Read Exception Status
0x00 Return Query Data
Restart Communication
0x01
Option
0x02 Return Diagnostic Register
Change ASCII Input
0x03
Delimiter
0x04 Force Listen Only Mode
Clear Counters and
0x0A
Diagnostic Register
0x0B Return Bus Message Count Read number of detected messages
Return Bus Communication
0x0C
Error Count
Return Bus Exception Error
0x0D
Count
Return Slave Message
0x0E
Count
Return Slave No Response
0x0F
Count
0x10 Return Slave NAK Count
0x11 Return Slave Busy Count
Return
0x12
Overrun Count
Read binary (R/W) devices
Read binary (RO) devices
Read 16 bit (R/W) register
Read 16 bit (RO) register
Write single binary device
Write single 16 bit register device
Read 1 byte of vendor specified data
CH1: M8060 - M8067
CH2: M8060 - M8062, M8438,
M8064 - M8067
Loop back function
Restart communication
- Clear all counters
- Recover from listen only mode
- Reset event log (if requested)
Read 16 bit register of vendor specified data
CH1: M8060 - M8067
CH2: M8060 - M8062, M8438,
M8064 - M8067
Note: High byte is unused.
Change ASCII mode End of Message
character. After response is mode slave will
change the delimiter.
Switch slave to Listen Only Mode
Note: When the slave enters Listen Only
Mode, all active communication controls are
turned off. While the device is in this mode,
any MODBUS messages addressed to it or
broadcast are monitored, but no actions will
be taken and no responses will be sent.
Clear all counters and the diagnostic registers
Read number of detected communication
errors
Read number of detected exception
conditions
Read number of received requests
Read "No Response" counter of the slave
Read NAK counter of the slave
Read "Busy" counter of the slave
Bus Character Read "Bus Character Overrun" counter of the
slave
9 Slave Specification
9.1 MODBUS Slave Command Code List
Details