Failure of PS in rack0 caused plant shutdown

Dear hdhosseini,

I can't correlate the redundant digital inputs to your plant shutdown.
Did both CPUs go to stop at this shutdown?
I can imagine that when a power supply of a CPU fails, the other power supply will be still OK and the standby CPU will take control.
What did you read in diagnostic buffer at this time?

regarding your uploaded project,
In hardware configuration the central digital input modules are configured as a redundant pair.
However the software misses some blocks like FB450,FB451 and FB452.
These blocks should be invoked in appropriate positions in user program according to what you can read in SIMATIC help of each FB.

hdhosseini

different addresses assigned to them but addresses for module in rack 0 is used in the user program.Failure of PS in rack0 caused plant shutdown.
So as I conclude the DI are not configured redundant.

They should always have different addresses.
This is different from S5-H where the same address could be given to a redundant pair.
In S7-400H, both CPUs are considered as a single one and then they share the same address area and each redundant module should have a unique address.
When you use addresses in user program, you will lawyers have to use the lower module address.

Best regards.

H-H