Function Code 10H - GE MM3 Instruction Manual

6 COMMUNICATIONS
Modbus Implementation: Preset Multiple Registers
MM3 Implementation: Store Multiple Setpoints
This function code allows multiple Setpoints to be stored into the MM3 memory. Modbus "registers" are 16-bit
(two byte) values transmitted high order byte first. Thus all MM3 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 MM3 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 17 to store the value 01F4 to setpoint address 1028 and the value
2710 to setpoint address 1029. After the transmission in this example is complete, MM3 slave 17 will have the
following setpoints information stored:
Address Data
1028 01F4
1029 2710
The master/slave packets have the following format:
Table 6–8: MASTER/SLAVE 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
SLAVE RESPONSE
SLAVE ADDRESS
FUNCTION CODE
DATA STARTING ADDRESS
NUMBER OF SETPOINTS
CRC
GE Power Management
BYTES EXAMPLE DESCRIPTION
1 11 message for slave 17
1 10 store setpoints
2 10 28 setpoint address 1028
2 00 02 2 setpoints = 4 bytes total
1 04 4 bytes of data
2 01 F4 data for setpoint address 1028
2 27 10 data for setpoint address 1029
2 33 23 CRC error code
BYTES EXAMPLE DESCRIPTION
1 11 message from slave 17
1 10 store setpoints
2 10 28 setpoint address 1028
2 00 02 2 setpoints
2 C7 90 CRC error code
MM3 Motor Manager 3
6.2 MM3 SUPPORTED FUNCTIONS

6.2.9 FUNCTION CODE 10H

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