Slave Diagnosis - Siemens SIMATIC IM 151/CPU Manual

Commissioning and Diagnostics
4.6

Slave Diagnosis

Interrupts with STEP 7 and an S7/M7 DP Master
You can trigger a process interrupt for the DP master from the user program of the
IM 151/CPU.
When you call SFC 7 ("DP_PRAL"), you activate an OB 40 in the user program of
the DP master. SFC 7 allows you to forward interrupt information in a double word
to the DP master; this information can then be evaluated in OB 40 in variable
OB40_POINT_ADDR. You can program the interrupt information as desired. A
detailed description of SFC 7 "DP_PRAL" can be found in the reference manual
entitled System Software S7-300/400 - System and Standard Functions .
Interrupts with STEP 7 and Another DP Master
If you run the IM 151/CPU with another DP master, interrupts are appear in the
station diagnosis of the IM 151/CPU (see Section 4.6.6). You must continue
processing the results of the diagnosis in the user program of the DP master.
Note
Note the following in order to be able to evaluate the diagnostic interrupt and
process interrupt via the station diagnosis when using a different DP master:
The DP master should be able to store diagnostic messages; this means that
diagnostic messages should be stored within the DP master in a ring buffer
store. If the DP master cannot store the diagnostic messages, only the most
recently received diagnostic message, for example, is stored.
With an IM 308-C as the DP master you cannot use process interrupts in the
station diagnosis.
Reference
You can find more information on the generally applicable slave diagnosis for the
ET 200S in the relevant section of the ET 200S Distributed I/O System manual.
You can also find out there which blocks you can use to request the slave
diagnosis.
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ET 200S Interface Module IM 151/CPU
A5E00058783-01