Function Code 08H - GE MOTOR MANAGER 2 Instruction Manual

6 COMMUNICATIONS
Modbus Implementation: Loopback Test
MM2 Implementation: Loopback Test
This function is used to test the integrity of the communication link. The MM2 will echo the request.
For example, consider a loopback test from slave 17:
Table 6–7: MASTER/SLAVE PACKET FORMAT FOR FUNCTION CODE 08H
MASTER TRANSMISSION
SLAVE ADDRESS
FUNCTION CODE
DIAG CODE
DATA
CRC
SLAVE RESPONSE
SLAVE ADDRESS
FUNCTION CODE
DIAG CODE
DATA
CRC
GE Power Management
BYTES EXAMPLE
1 11
1 08
2 00 00
2 00 00
2 E0 0B
BYTES EXAMPLE
1 11
1 08
2 00 00
2 00 00
2 E0 0B
MM2 Motor Manager 2
6.2 MODBUS FUNCTIONS

6.2.7 FUNCTION CODE 08H

DESCRIPTION
message for slave 17
loopback test
must be 00 00
must be 00 00
CRC error code
DESCRIPTION
message from slave 17
loopback test
must be 00 00
must be 00 00
CRC error code
6
6-11