Software Requirements - Siemens SIMATIC S7-400 Manual

3.3.3

Software requirements

Software Requirements for System Modifications during Operation
To be able to make configuration changes in RUN, the user program must meet the following
requirement: It must be written so that, for example, station failures, module faults or
timeouts do not cause the CPU to change to STOP.
The following OBs must be available on your CPU:
● Hardware interrupt OBs (OB 40 to OB 47)
● Time jump OB (OB80)
● Diagnostic interrupt OB (OB82)
● Remove/insert OB (OB83)
● CPU hardware fault OB (OB84)
● Program execution error OB (OB85)
● Rack failure OB (OB86)
● I/O access error OB (OB122)
S7-400 Automation System, CPU Specifications
Manual, 10/2006, 6ES7498-8AA04-8BA0
Special functions of a CPU 41x
3.3 System modifications during operation
3-9