Function Code 16 - Performing Commands - GE Power Quality Meter Series Instruction Manual

7 MODBUS COMMUNICATIONS
Some PLCs may not support execution of commands using function code 5 but do support storing multiple set-
points using function code 16. To perform this operation using function code 16 (10H), a certain sequence of
commands must be written at the same time to the PQM. The sequence consists of: Command Function regis-
ter, Command operation register and Command Data (if required). The Command Function register must be
written with the value of 5 indicating an execute operation is requested. The Command Operation register must
then be written with a valid command operation number from the list of commands shown in the memory map.
The Command Data registers must be written with valid data if the command operation requires data. The
selected command will be executed immediately upon receipt of a valid transmission.
MESSAGE FORMAT AND EXAMPLE:
Perform a reset on PQM (operation code 1).
Table 7–8: MASTER/SLAVE PACKET FORMAT FOR PERFORMING COMMANDS
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

7.2.9 FUNCTION CODE 16 - PERFORMING COMMANDS

BYTES EXAMPLE
1 11
1 10
2 00 80
2 00 02
1 04
2 00 05
2 00 01
2 B0 D6
BYTES EXAMPLE
1 11
1 10
2 00 80
2 00 02
2 46 7A
PQM Power Quality Meter
7.2 MODBUS FUNCTIONS
DESCRIPTION
message for slave 17
store multiple setpoints
setpoint address 1028
2 setpoints = 4 bytes total
4 bytes of data
data for address 0080
data for address 0081
CRC error code
DESCRIPTION
message from slave 17
store multiple setpoints
setpoint address 00 80
2 setpoints
CRC error code
7
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