Chapter 6. Serial I/O, SNP & RTU Protocols
GFK-2222AD
April 2018
241
Message (06): Preset Single Register
Format:
Address
Register
Number
Data
Error Check
Func
06
Query
Hi
Hi
Lo
Lo
Normal Response
Address
Register
Number
Data
Error Check
Func
06
Hi
Hi
Lo
Lo
Figure 57: RTU Preset Single Register Message Format
Query:
▪
An Address 0 indicates a broadcast request. All slave stations process a broadcast request and no
response is sent.
▪
The function code is equal to 06.
▪
The Register Number field is two bytes in length. It may be any value less than the highest register
available in the attached CPU. It is equal to one less than the number of the register to be preset.
▪
The Data field is two bytes in length and contains the value that the register specified by the Register
Number Field is to be preset to. The first byte in the Data field contains the high order byte of the
preset value. The second byte in the Data field contains the low order byte.
Response:
▪
The normal response to a preset single register query is identical to the query.