Diagnostics
7-4
IM 178-4
C79000-G7076-C178-01
Diagnostics When Using an S7/M7 DP Master
Requesting slave diagnostics is particularly useful when you have enabled the
diagnostic interrupt in the parameter assignment. If the IM 178-4 detects an error,
it provides external diagnostic data if this has been selected in the parameter
assignment.
You can request the slave diagnostic data using SFC13 “DPNRM_DG” (see
System and Standard Functions reference manual).
7.2.2
Structure of the First 6 Bytes of the Slave Diagnostic Data
Structure of Station Status 1
Station status 1 provides information about the DP slave and has the following
structure:
Table 7-3
Structure of Station Status 1 (Byte 0)
Bit
Meaning
Remedy
0
1: The DP slave cannot be
accessed by theDP master.
S
Is the correct PROFIBUS
address set on the DP slave?
S
Is the bus connector plugged in?
S
Voltage on the DP slave?
S
RS 485 repeater set correctly?
S
Reset the DP slave
1
1: The DP slave is not ready for
data exchange
Wait, the DP slave is currently
starting up.
2
1: The configuration data sent by
the DP master to the DP slave do
not match the structure of the DP
slave.
Correct station type or correct
structure of the DP slave entered in
the configuration?
3
1: Device-related and/or ID-related
diagnostic data from the IM 178-4
exist.
You can read out the diagnostic
data.
4
1: The function is not supported, for
example modifying the PROFIBUS
address with the software.
Check the configuration.
5
1: The DP master cannot interpret
the response of the DP slave.
Check the physical properties of the
bus.