Hitachi WJ200-001S Instruction Manual page 543

Ver.3− − − − 34
(2) Writing Holding Register [06h] 、 T arget Register: External Register
Query:
No
1 Slave address
2 Function code
3 Register start address
(high order)
4 Register start address
(low order)
5 Change data (high order)
6 Change data (low order)
7 CRC-16 (high order)
8 CRC-16 (low order)
Response:
No
1 Slave address
2 Function code
3 Register start address
(high order)
4 Register start address
(low order)
5 Change data (high order)
6 Change data (low order)
7 CRC-16 (high order)
8 CRC-16 (low order)
After the Modbus communication above, -1% is observed by the Operator.
Field Name
Field Name Example
Example
(Hex)
01
06
40
Register address value = Register
Number - 1
02
FFFFh represents -1 in two's
FF
compliment
FF
3C
7A
(Hex)
01
06
40
Register address value = Register
02 Number - 1
FFFFh
FF
compliment
FF
3C
7A
represents -1 in two's