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WPMZ Series Modbus communication instruction manual
IM-0862-02
Number of pages:109
21
4.
Communication example
The actual communication example of each message is shown below.
4-1.
WPMZ-5/6
4-1-1.
Acquire measurement data
When acquiring measurement data, it is as follows.
1.
Data acquisition communication
Here is an example of obtaining the instantaneous display value of pulse input A.
Pulse input A instantaneous display value is defined in the input register, so 04 H (input register
readout [read only address]) is used as the function code.
Pulse input A instantaneous display value acquisition (address: 0191 H)
First, send a message from the master to the slave (module).
Since the data size is 4 bytes, the number of read words is 2.
Table 4.1 Pulse input A Acquire instantaneous display value [Send]
n a me
Tran smi tte d
da ta
S l a v e ID
0 1 H
Fu n c ti on c o de
0 4 H
A d d r e s s
U p p e r
0 1 H
Lo w e r
9 1 H
Nu m be r of w or d s t o
be re a d
U p p e r
0 0 H
Lo w e r
0 2 H
E r r o r c h e c k
( C R C - 1 6 )
Lo w e r
2 1 H
U p p e r
DA H
After that, 2 words of data are returned from the slave (module) to the master.
Table 4.2 Pulse input A Acquire instantaneous display value [Receive]
n a me
Re c e i ve d
da ta
S l a v e ID
0 1 H
Fu n c ti on c o de
0 4 H
N u m b e r o f b y te s r e a d
0 4 H
Da ta o f th e fi r s t
wor d
U p p e r
0 0 H
Lo w e r
0 1 H
Da ta o f th e se c on d
wor d
U p p e r
E2 H
Lo w e r
4 0 H
E r r o r c h e c k
( C R C - 1 6 )
Lo w e r
E3 H
U p p e r
1 4 H
The acquired data is continued for two words, and it is as follows.
Table 4.3 Acquired data
Read value
(hexadecimal number)
Decimal number
0001E240H
123456