Online documentation and redundancy switch-over
- Repeat the 'Online Documentation'
The 'Online Documentation' must be repeated if a redundancy switch-over of the CL coupler occurs between the start and the end. This can be checked with the messages on the alarm page.
The described problems cannot be solved with software changes, as in this case the data transfer from the coupling to the operator station takes place via messages which may be broken off in the case of a station failure.
If a redundancy switch-over of this CL coupler is carried out during a running ‘Online Documentation’ of the functions of a redundant network coupler, then it is very possible that a function is missing in the stored file. Data can also be lost through a redundancy switch-over during a running fault-sequence log (to be more exact: while the values are being collected from the ‘CL’). However, the fault-sequence log itself also functions properly in the case of redundancy.