CHAPTER 11: MODBUS PROTOCOL
FUNCTION CODE 10H (STORE MULTIPLE SETPOINTS)
8 SERIES PROTECTIVE RELAY PLATFORM – COMMUNICATIONS GUIDE
11-9
Function Code 10H (Store Multiple Setpoints)
Modbus Implementation: Preset Multiple Registers
8 Series relay Implementation: Store Multiple Setpoints
The function code allows multiple Setpoints to be stored into the 8 Series relay memory.
Modbus “registers” are 16-bit (two byte) values transmitted high order byte first. Thus all
8 Series relay setpoints are sent as two bytes. The maximum number of Setpoints that can
be stored in one transmission is dependent on the slave device. Modbus allows up to a
maximum of 60 holding registers to be stored. The 8 Series relay response to this function
code is to echo the slave address, function code, starting address, the number of Setpoints
stored, and the CRC.
For example, consider a request for slave 254 to store the value 00 0A to setpoint address
41 DB and the value 00 64 to setpoint address 41 DC. After the transmission in this
example is complete, 8 Series relay slave 254 will have the following setpoints information
stored:
Table 11-14: Master Packet Format for Function Code 10H
Table 11-15: Slave Packet Format for Function Code 10H
ASE 2000 V2 Example
--> 00 00 00 00 00 0B FE 10 41 DB 00 02 04 00 0A 00 64
--> 00 00 00 00 00 06 FE 10 41 DB 00 02
Address
Data
41 DB
00 0A
41 DC
00 64
MASTER TRANSMISSION
BYTES
EXAMPLE
DESCRIPTION
SLAVE ADDRESS
1
FE
message for slave 254
FUNCTION CODE
1
10
store setpoints
DATA STARTING ADDRESS
2
41 DB
setpoint address 41 DB
NUMBER OF SETPOINTS
2
00 02
2 setpoints – 4 bytes total
BYTE COUNT
1
04
4 bytes of data
DATA 1
2
00 0A
data for setpoint address 41 DB
DATA 2
2
00 64
data for setpoint address 41 DC
CRC (low, high)
2
91 ED
CRC error code
SLAVE RESPONSE
BYTES
EXAMPLE
DESCRIPTION
SLAVE ADDRESS
1
FE
message from slave 254
FUNCTION CODE
1
10
store setpoints
DATA STARTING ADDRESS
2
41 DB
setpoint address 41 DB
NUMBER OF SETPOINTS
2
00 02
2 setpoints
CRC (low, high)
2
31 C0
CRC error code