same digital output for ON and OFF

[mahone]

hi all,

what is the best way to implement ON OFF when there is only one DO?
i'm using rslogix 5000. there is a feedback if the ON is active

anyone have any sample code i can have a look?

thanks

 

[Geoff White]

The best way is to ask a question that is less vague.

Everything is ON OFF in a PLC.

 

[cardosocea]

If I understand you correctly, perhaps with relay logic on the output?

If that output powers a relay with a NO and a NC contact, you can get two signals that power based on an output of the PLC. If wired correctly, when the output is ON, the NO contact will be closed and when the output is OFF the NC contact will be closed.

I'm assuming you'd want this to activate a two position valve without a spring return, for example.

 

[mahone]

I think I have stated the question wrong.

I have a CCR(constant current regular) which has 5 level of brilliancy. In order to activate a brilliancy level, a 24 vdc must be applied. But to off the same brilliancy it takes 24 vdc on the same input. If the ON feedback is active when the input is activated second time the CCR will turn that level OFF. I’m working on a ladder based logic for this

 

[mdim]

As it seems you have feedback. In this case, I am pretty sure that if you write diagram with the possible states, you will figure it by yourself