Slave Function; Automatic Response Function - Mitsubishi QJ71MB91 User Manual

5
FUNCTIONS

5.3 Slave Function

This section explains the functions of the QJ71MB91 acting as a MODBUS

5.3.1 Automatic response function

By the automatic response function, the QJ71MB91 (slave function) automatically
executes the processing requested by the function code (
message from the master, and returns a response message to the master.
For device read/write or exception status read, use the MODBUS
function. (
Programmable
controller CPU
No sequence
program
required
Device memory
5
- 17 5.3 Slave Function
5.3.1 Automatic response function
Section 5.3.2)
QJ71MB91
(Slave function)
1)
Receiving
request message
2)
Function
code
identification
3)
Requested
processing execution
4)
Transmitting
response message
Figure 5.12 Automatic response function
Request message (function code)
Response message
RS-232, RS-422 or RS-485
slave.
Section 4.1) of a request
device assignment
MODBUS R
master device