Function Code 08H - GE MM3 Instruction Manual

6.2 MM3 SUPPORTED FUNCTIONS
Modbus Implementation: Loopback Test
MM3 Implementation: Loopback Test
This function is used to test the integrity of the communication link. The MM3 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
6
6-10
BYTES EXAMPLE DESCRIPTION
1 11 message for slave 17
1 08 loopback test
2 00 00 must be 00 00
2 00 00 must be 00 00
2 E0 0B CRC error code
BYTES EXAMPLE DESCRIPTION
1 11 message from slave 17
1 08 loopback test
2 00 00 must be 00 00
2 00 00 must be 00 00
2 E0 0B CRC error code
MM3 Motor Manager 3
6 COMMUNICATIONS

6.2.8 FUNCTION CODE 08H

GE Power Management