Function Code 10H (Store Multiple Setpoints) - GE Multilin 850 Communications Manual

CHAPTER 11: MODBUS PROTOCOL

Function Code 10H (Store Multiple Setpoints)

8 SERIES PROTECTIVE RELAY PLATFORM – COMMUNICATIONS GUIDE
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:
Address
41 DB
41 DC
Table 11-14: Master Packet Format for Function Code 10H
MASTER TRANSMISSION
SLAVE ADDRESS
FUNCTION CODE
DATA STARTING ADDRESS
NUMBER OF SETPOINTS
BYTE COUNT
DATA 1
DATA 2
CRC (low, high)
Table 11-15: Slave Packet Format for Function Code 10H
SLAVE RESPONSE
SLAVE ADDRESS
FUNCTION CODE
DATA STARTING ADDRESS
NUMBER OF SETPOINTS
CRC (low, high)
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
FUNCTION CODE 10H (STORE MULTIPLE SETPOINTS)
Data
00 0A
00 64
BYTES EXAMPLE
1 FE
1 10
2 41 DB
2 00 02
1 04
2 00 0A
2 00 64
2 91 ED
BYTES EXAMPLE
1 FE
1 10
2 41 DB
2 00 02
2 31 C0
DESCRIPTION
message for slave 254
store setpoints
setpoint address 41 DB
2 setpoints – 4 bytes total
4 bytes of data
data for setpoint address 41 DB
data for setpoint address 41 DC
CRC error code
DESCRIPTION
message from slave 254
store setpoints
setpoint address 41 DB
2 setpoints
CRC error code
11-9