Process Of Updating - Siemens SIMATIC S7-400H Manual

Note
If you have not changed the type of load memory or enlarged the main memory or
the load memory on the standby CPU this will not switch to RUN mode but instead
will relapse into STOP mode with a corresponding diagnostics buffer entry.
If you have not changed the operating system on the standby CPU this will not
switch to RUN mode but instead will relapse into STOP mode with a
corresponding diagnostics buffer entry.
No master/standby switch-over will take place and the CPU that has been the
master CPU up to that point will remain in RUN mode.
5.2.2

Process of Updating

What happens during update?
On update the execution of the communication functions and of the OBs is
restricted by section. Similarly, all the dynamic data (content of the data blocks,
timers, counters and memory markers) are transferred to the standby CPU.
The update procedure is as follows:
1. All asynchronous SFCs that have recourse to data records of I/O modules
(SFC 13, 51, 55 to 59) are given a "negative" acknowledgement until the end
of the update:
– A current job returns BUSY = TRUE. It will be fully executed after the update
is complete.
– A job interrupted during the update will return the value W#16#80C3
(SFCs 13, 55 to 59) or W#16#8085 (SFC 51) once the update is complete.
With these return values the jobs should be repeated by the user program.
– A job that you want to start during the update will be rejected with the return
value W#16#80C3 (SFCs 13, 55 to 59) or W#16#8085 (SFC 51). With these
return values the jobs should be repeated by the user program once the
update is complete.
2. Notification functions are delayed until the end of the update (see list below).
3. The execution of the OB 1 and of all OBs up to and including priority class 15
is delayed.
With watchdog interrupts, the generation of new OB requests is inhibited so
that no new watchdog interrupts are stored and, consequently, no new request
errors occur.
Not until the end of the update is a maximum of one request generated and
processed for each watchdog interrupt OB. The time stamp of the watchdog
interrupts that are generated after a delay cannot be evaluated.
S7-400H Programmable Controller Fault-Tolerant Systems
A5E00068197-04
Link-up and Update
5-9