Slave Function; Related Devices; List Of Related Devices - Mitsubishi Electric MELSEC iQ-F FX5 User Manual

7.2

Slave Function

This function performs operations according to the supported function code by communication with the master station.
For the supported function codes, refer to Page 21 List of supported MODBUS standard functions.
7.3

Related Devices

In this section, the functions of the special registers and special relays are described for MODBUS serial communication.

List of related devices

Special relays
The table shows the special relays used for the FX5 MODBUS serial communication.
■Only for FX5
Device number
CH1 CH2 CH3 CH4
SM8500 SM8510 SM8520 SM8530
SM8800 SM8810 SM8820 SM8830
SM8801 SM8811 SM8821 SM8831
SM8802 SM8812 SM8822 SM8832
SM8861 SM8871 SM8881 SM8891
R: Read only, R/W: Read/Write
*1 The devices become R/W when a latch is set and R when a latch is not set.
■For FX3 compatibility
Device number
CH1 CH2
SM8029
SM8401 SM8421
SM8402 SM8422
SM8403 SM8423
SM8063 SM8438
SM8408 SM8428
SM8409 SM8429
R: Read only
Name Valid
Serial communication error Master/
Slave
During MODBUS serial Master
communication
Retry Master
Timeout Master
Host station number latch Slave
setting valid
Name Valid
Instruction execution Master
complete
During MODBUS Master
communication
MODBUS communication Master
error
MODBUS communication Master/
error (latched) Slave
Serial communication error Master/
Slave
Retry Master
Timeout Master
Details
Turns on when an error occurs during the serial
communication.
Turns on when the instruction is started until the instruction
execution complete flag is turned on during MODBUS
serial communication.
Turns on while the master sends retries when the slave
fails to respond until timeout setting time.
Turns on if a response timeout occurs.
Turns on when the latch setting is set to "Latch".
Details
Turns on if the processing of an instruction is completed.
Turns on when the instruction is started until the instruction
execution complete flag is turned on during MODBUS
serial communication.
Turns on when an error occurs during MODBUS serial
communication.
Turns on once an error occurs during MODBUS serial
communication.
Turns on once an error occurs during MODBUS serial
communication.
Turns on while the master sends retries when the slave
fails to respond until timeout setting time.
Turns on if a response timeout occurs.
R/W
R
R
R
R
*1
R/W
R
R
R
R
R
R
R
7 FUNCTION
35
7.2 Slave Function
7