Code 08 - Execute Diagnostics; Figure 2-21 Execute Diagnostics Example - Request; Figure 2-22 Execute Diagnostics Example - Response - Siemens SIMATIC TI505 User Manual

Code 08 —
Execute
Diagnostics
! WARNING
SIMATIC TI505/TI500 MODNIM User Manual
Code 08 enables diagnostic information to be retrieved to conduct network
testing. This function does not affect the operation of the PLC, but may have
significant effects on the operation of the MODNIM. Where these effects
impact upon the operation of the MODNIM, they are described with the
details for that diagnostic code.
Because of differences in memory mapping between Modbus PLCs
and SIMATIC TI PLCs, you should be quite certain of the effects of
the broadcast command before issuing it.
Example:
Request: 02 08 0000 B405 XXXX
Figure 2-21 Execute Diagnostics Example — Request
This example shows a request to conduct diagnostic test 0000. This is the
loopback query, where the outgoing message field is returned unchanged.
Response: 02 08 0000 B405 XXXX
Figure 2-22 Execute Diagnostics Example — Response
Checksum (XXXX)
Information Field (B405)
Diagnostic code (0000)
Function code (08)
Slave address (02)
Checksum (XXXX)
Information Field (B405)
Diagnostic code (0000)
Function code (08)
Slave address (02)
Modbus Commands 2-19