Technical data

Table Of Contents
Generating Block-Related Messages
System Software for S7-300/400 System and Standard Functions - Volume 2/2
A5E00739858-01
24-25
24.11 How the SFBs for Generating Block-Related Messages
React to Problems
Connection Breakdown
The connections assigned to the SFB instances are monitored for breakdown. If a
connection breaks down, the stations involved are removed from the internal CPU
list of stations logged on for block-related messages. Any messages pending for
these stations are deleted.
If other stations are still logged on following a connection breakdown, they continue
to receive messages. The SFBs only stop sending messages when there are no
more connections to any logged on stations. The ERROR and STATUS output
parameters indicate this situation (ERROR = 1, STATUS = 1).
Error Interface to the User Program
If an error occurs during the execution of an SFB for generating block-related
messages, the ERROR output parameter is set to 1 and the STATUS output
parameter has the corresponding error identifier. You can evaluate this error
information in your program.
Examples of possible errors:
Sending not possible due to lack of resources
Error accessing one of the signals to be monitored.