5
FUNCTIONS
5.2 Master Function
5.2.2 Communication by dedicated instructions
5
- 16
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
TA
NDA
RD
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)
5.2.2 Communication by dedicated instructions
The dedicated instructions allow reading/writing of MODBUS devices at any timing with a
sequence program.
The following is a list of available dedicated instructions.
Figure 5.11 Communication by dedicated instruction
Table5.4 Dedicated instruction list
Dedicated
instruction
Description
Reference
MBRW
Issues a MODBUS
device read/write request message to a slave.
MBREQ
With this instruction, a request message can be sent to a slave in any
given Protocol Data Unit format.
[Z.MBRW ]
Command
400500
MODBUS slave device
Holding register
1234
H
R
Programmable
controller CPU
Device memory
1234
H
QJ71MB91
(Master function)
Request message (Read request for holding register 400500)
Response message (Holding register 400500 = 1234
H
)
RS-232, RS-422 or RS-485
Содержание QJ71MB91
Страница 1: ......
Страница 2: ......
Страница 366: ...App 14 Appendix 4 External Dimensions APPENDICES Memo ...
Страница 371: ......
Страница 372: ......