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4. Operation Method
RS485 Communication Function
5.2 Write communication example
Example) Request message:
A request for setting "SV to 135" (writing 135) is transmitted to the unit set at address 03.
Reply message from the unit to this request message: Information that the request message has
been received is returned.
・
Confirm that the data has been properly written by reading it separately.
① ② ③ ④ ⑤ ⑥ ⑦
S
T
X
0
3
A
C
K
E
T
X
B
C
C
① ② ⑧ ⑥ ⑦
Code
Symbol/Data
ASCII code
*2
①
Start Code
STX
02H
②
Address
03
30H 33H
③
Request (Write)
W
57H
④
Identifier
*1
PV1
53H 56H 31H
⑤
Numeric Data
00135
30H 30H 31H 33H 35H
⑥
End Code
ETX
03H
⑦
BCC data
Request
56H
Reply
04H
⑧
Acknowledgement code
ACK
06H
*1): See "7. List of Identifiers/Commands."
*2): For ASCII codes, see "8. List of ASCII Codes."
S
T
X
0
3
W
S
V
1
0
0
1
3
5
E
T
X
B
C
C
Write request message
(transmitted from the host computer)
Reply message (returned from the unit)