Hitachi EH-150 Series - Page 111

Chapter 6 Communication Mode
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Modbus Slave
 Function code 0x06 (Preset Single Register)
For EH-SIO, this function code means “Write 1 word of internal output (WM)” or “Write 1 word of internal output
(WR)”. In case of broadcasting, the same output in each slave will be written.
« Note »
The type of internal output which accesses by this query is decided by the parameter (communication mode) in
initial setting. (Writing to “WR” by function code 0x06 is function which is supported from software ver. 3.0.)
(1) Query
The query message data field is the value to change. In case of a broadcast, please set the slave address field as 00.
« Note »
A start address should specify I/O number of WM. (For WM20 / WR20, the address is specified as H0020.)
(2) Response
When a query is processed normally, the response and the query become the same. In broadcasting, a response is
not returned.
« Note »
If requested address is not assigned as internal output, exception response will be returned.
(3) Example
Write H19CF to WMA2 / WRA2 in the slave 27.
Query
Response
Field name
Example
(HEX)
Field name
Example
(HEX)
Slave address
1 B
Slave address
1 B
Function code
0 6
Function code
0 6
Register head address (upper)
0 0
Register head address (upper)
0 0
Register head address (lower)
A 2
Register head address (lower)
A 2
Change data (upper)
1 9
Change data (upper)
1 9
Change data (lower)
C F
Change data (lower)
C F
Error check
[CRC]
Error check
[CRC]
When a query is executed properly, the response and the query become the same.