IDEC FC6A-C16K1CE Communications Manual page 141

Function Code 06 (Preset Single Register)
Function code 06 changes word device data of D (data register).
Communication Frame
Request from Modbus RTU Master
Slave No.
xxh
ACK Reply from Modbus RTU Slave
Slave No.
xxh
NAK Reply from Modbus RTU Slave
Slave No.
xxh
Communication Example
Write 8000 to data register D1708.
D1708 → (1708 – 0) + 400001 = 401709
Modbus address: 401709
Purpose
Extract lower 5 digits → 1709
1709 – 1 = 1708 = 6ACh
Communication frame address: 06ACh
Condition Slave No. 8
Modbus RTU Mode
•
Request from Modbus RTU Master
ACK Reply from Modbus RTU Slave
NAK Reply from Modbus RTU Slave
Function Code Address
06h xxxxh
Function Code Address
06h xxxxh
Function Code Error Code
86h xxh
08 06 06AC 1F40 (CRC)
08 06 06AC 1F40 (CRC)
08 86 xx (CRC)
FC6A S M S A
ERIES ICRO MART LL
New Data
xxxxh
Acknowledge
Data
xxxxh
- -O T C
IN NE YPE OMMUNICATION
6: M
ODBUS
M FC9Y-B1730
ANUAL
C
OMMUNICATION
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