Siemens SIMATIC IM 151/CPU Manual page 41

Functionality in Direct Communication
The IM 151/CPU offers the following functionality in direct communication:
Passive sender:
When requested by the DP master, the IM 151/CPU, as the DP slave, sends
the process outputs configured for direct communication as a broadcast frame
to all bus nodes. Other recipients filter the relevant data from this broadcast
frame.
Recipient:
Filtering of the data (1 to 32 bytes) from the broadcast frame from a maximum
of 8 senders configured by means of STEP 7 as relevant for direct
communication. One pick-up is possible per sender.
Note
The system load increases with the number of configured recipients. The total
system load is specified as a multiplying factor for the run times of the individual
statements.
Diagnostics in Direct Communication
Only the results of connection monitoring can be used in the diagnostics of the DP
slaves configured for direct communication, because diagnostic messages of the
DP slaves that have been listened in on are only reported to the DP master.
The asynchronous OB 86 is called in the event of station failure and reintegration.
If data is accessed during a station failure of the sender, an I/O access error is
detected and OB 122 is called. Only the identifiers "module plugged" and "module
available" are relevant for the module status data.
ET 200S Interface Module IM 151/CPU
A5E00058783-01
ET 200S in the PROFIBUS Network
3-11