Sel 751A - Table E.16 06 H Preset Single Register Command; Table E.17 Responses to 06 H Preset Single Register Query Errors; Table E.18 10 H Preset Multiple Registers Command

E.14
SEL-751A Relay Instruction Manual Date Code 20100129
Modbus RTU Communications
Communications Protocol
The relay responses to errors in the query are shown in Table E .17 .
10h Preset Multiple
Registers Command
This function code works much like code 06h, except that it allows you to
write multiple registers at once, up to 100 per operation. If you are
accustomed to 4X references with the function code, for six-digit addressing,
simply add 400001 to the standard database addresses.
Table E.16 06h Preset Single Register Command
Bytes Field
Queries from the master must have the following format:
1 byte Slave Address
1 byte Function Code (06h)
2 bytes Register Address
2 bytes Data
2 bytes CRC-16
Table E.17 Responses to 06h Preset Single Register Query Errors
Error Error Code Returned
Communication Counter
Increments
Illegal register address Illegal Data Address (02h) Invalid Address Illegal Write
Illegal register value Illegal Data Value (03h) Illegal Write
Format error Illegal Data Value (03h) Bad Packet Format
Table E.18 10h Preset Multiple Registers Command
Bytes Field
Queries from the master must have the following format:
1 byte Slave Address
1 byte Function Code (10h)
2 bytes Starting Address
2 bytes Number of Registers to Write
1 byte Number of Bytes of Data (n)
n bytes Data
2 bytes CRC-16
A successful response from the slave will have the following format:
1 byte Slave Address
1 byte Function Code (10h)
2 bytes Starting Address
2 bytes Number of Registers
2 bytes CRC-16