Mitsubishi QJ71MB91, User Manual

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4
MODBUS(R) STANDARD FUNCTIONS
4.1 MODBUS(R) Standard Function Support List
4
- 8
1
O
VER
VIE
W
2
SYS
T
E
M
CO
NF
IG
U
R
A
T
IO
N
3
S
P
E
CIFICA
TI
ONS
4
MODB
US
(R)
S
TAN
DAR
D
FUN
C
TIO
N
S
5
FUNC
TI
ON
6
PR
E
-O
PER
A
T
ION
AL
P
R
OCED
URE
S A
ND
SE
TTINGS
7
P
A
RA
MET
E
R S
E
TTI
N
G
8
UTIL
ITY P
A
CK
AGE
(G
X Co
nf
ig
u
rat
o
r-M
B)
: Supported : Supported with restrictions : Not 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
H
)
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.
(Continued on next page)
Table 4.3 MODBUS standard functions available for access to MELSECNET/H remote I/O station (continued)
Function
code
(Sub code)
Sub-function
code
Function
Master function
Slave function
*1
Automatic
communication
function
MBRW
instruction
MBREQ
instruction
08
00 Return query data
01 Restart communications option
02 Return diagnostic register
03 Change ASCII input delimiter
04 Force listen only mode
10
Clear counters and diagnostic
register
11 Return bus message count
12
Return bus communication
error count
13
Return bus exception error
count
14 Return slave message count
15
Return slave no response
count
16 Return slave NAK count
17 Return slave busy count
18
Return bus character overrun
count
19 Return IOP overrun error count
20 Clear overrun counter and flag