Dead PU410 doesn't toggle redundancy switchover
Thank you in advance!
If that is not the case, you should file a support case with your regional ABB support center to obtain assistance.
I guess that your observation is correct, i.e. the connectivity server still running does not recognize that it has lost connectivity due to power failure on the connected PU410.
But in a redundant connectivity server setup, the other connectivity server maintains connectivity provided that the connected PU410 is still running.
On the other hand, an inappropriate consequence might be that 800xA Clients, fetching OPC Data from the connectivity server that has lost connectivity due to power failure on the connected PU410, will loose OPC Data to Graphic Displays PG2 (remember that the connectivity server is still running and the 800xA Service Provider with respect to OPC Data is still OK, but connectivity has been lost due to power failure on the connected PU410 and 800xA Clients does not automatically switch over to the connectivity server with OPC Data available). Please correct me if I am wrong in this observation.
To my knowledge there is no possible configuration that will prevent / circumvent the above described situation.
A workaround is the following:
I will recommend that you ensure redundant power to the PU410.
This can be achieved with e.g. one "APC Automatic Transfer Switch" which has two inputs 220 VAC (Power A and Power B) and one output 220 VAC for the PU410.
I hope that the above might help you.