Mitsubishi Electric QJ71MB91 User Manual page 63

4
MODBUS STANDARD FUNCTIONS
Table 4.3 MODBUS standard functions available for access to MELSECNET/H remote I/O station (continued)
Function
Sub-function
code
code
(Sub code)
00 Return query data
01 Restart communications option
02 Return diagnostic register
03 Change ASCII input delimiter
04 Force listen only mode
Clear counters and diagnostic
10
register
11 Return bus message count
Return bus communication
12
error count
08
Return bus exception error
13
count
14 Return slave message count
Return slave no response
15
count
16 Return slave NAK count
17 Return slave busy count
Return bus character overrun
18
count
19 Return IOP overrun error count
20 Clear overrun counter and flag
Automatic
Function
communication
: Supported
* 1 The access target is the MELSECNET/H remote I/O station.
When the MELSECNET/H remote master station is the access target, available functions are the
same as those shown in (2).
* 2 Accessing the MODBUS device that is not supported by the MELSECNET/H remote I/O station
results in error completion. (Exception code: 04
If the access target is the MELSECNET/H remote master station, it can be assigned to the control
CPU device of the MELSECNET/H remote master station.
4.1 MODBUS Standard Function Support List
Master function
MBRW
instruction
function
: Supported with restrictions
)
H
Slave function
MBREQ
instruction
: Not supported
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