GE 239

GE Multilin 239 Motor Protection Relay 7-5
7 COMMUNICATIONS 7 COMMUNICATIONS
7
Slave Response Bytes Example (hex)
SLAVE ADDRESS - 1 byte 11 message from slave 11
FUNCTION CODE - 1 byte 03 read registers
BYTE COUNT - 1 byte 06 3 registers = 6 bytes
DATA 1 - 2 byte 00 00 bit set corresponding to command 13
DATA 2 - 2 bytes 00 00 value in address 006C
DATA 3 - 2 bytes 00 00 value in address 006D
CRC - 2 bytes EC B5 CRC calculated by slave
7.9 05: EXECUTE OPERATION
• Modbus Implementation:Force Single Coil
• 239 Implementation: Execute Operation
This function code allows the master to request a 239 to perform specific command operations. The
command numbers listed in the Commands area of the memory map correspond to operation code
for function code 05.
The operation commands can also be initiated by writing to the Commands area of the memory map
using function code 16. Refer to Section 7.14: 16: PERFORMING COMMANDS on page 7–10 for
complete details.
a) MESSAGE FORMAT AND EXAMPLE
Reset 239 (operation code 1).
Master Transmission Bytes Example (hex)
SLAVE ADDRESS - 1 byte 11 message for slave 11
FUNCTION CODE - 1 byte 05 execute operation
OPERATION CODE - 2 bytes 00 reset command (operation code 1)
01
CODE VALUE - 2 bytes FF perform function
00
CRC - 2 bytes DF CRC calculated by the master
6A
Slave Response Bytes Example (hex)
SLAVE ADDRESS - 1 byte 11 message from slave 11
FUNCTION CODE - 1 byte 05 execute operation
OPERATION CODE - 2 bytes 00 reset command (operation code 1)
01
CODE VALUE - 2 bytes FF perform function
00
CRC - 2 bytes DF CRC calculated by slave
6A