please advise if this can be achieved with PLC outputs?

I know that we can configure the outputs to keep last state in case of PLC failure or software problem, but what will happen if we can lose the module power supply?

 

Kind of an unclear inquiry, you can save state with some PLCs that have persistent or non-volatile memory, But if the power goes away the outputs won't work until it is restored. Does this answer the question?

Regards
cww

 

no. buy you can latch and unlatch a relay with two plc outputs and when the plc dies the relay will stay as is.

--
Bob

 

imho you should ALWAYS shut down outputs in software when you lose power for the physical outputs. the situation when some motor is running, then suddenly stops due to power loss on the control and then starts again automatically when the power is restored is potentially dangerous. by my opinion it's not a good practice to set the outputs to retain the value when there's a failure. i'd rather hardwire such functionality. depends on your safety considerations though.