GE 239

7-10 239 Motor Protection Relay GE Multilin
7 COMMUNICATIONS 7 COMMUNICATIONS
7
7.14 16: PERFORMING COMMANDS
Some PLCs may not support execution of commands using function code 5 but do support storing
multiple setpoints 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 239. The sequence consists
of: Command Function register, 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 execute
immediately upon receipt of a valid transmission.
a) MESSAGE FORMAT AND EXAMPLE
Master Transmission Bytes Example (hex)
SLAVE ADDRESS - 1 byte 11 message for slave 11
FUNCTION CODE - 1 byte 10 store Setpoints
DATA STARTING ADDRESS - 2 bytes 00 Setpoint address 0080
80
NUMBER OF SETPOINTS - 2 bytes 00 2 Setpoints (4 bytes total)
02
BYTE COUNT - 1 byte 04 4 bytes of data
DATA 1 - 2 bytes 00 data for address 0080
05
DATA 2 - 2 bytes 00 data for address 0081
01
CRC - 2 bytes 7E CRC calculated by the master
CE
Slave Response
SLAVE ADDRESS - 1 byte 11 message from slave 11
FUNCTION CODE - 1 byte 10 store Setpoints
DATA STARTING ADDRESS - 2 bytes 00 Setpoint address 0080
80
NUMBER OF SETPOINTS - 2 bytes 00 2 Setpoints
02
CRC - 2 bytes 42 CRC calculated by slave
B0