Discrete input and process pause

[ssgross]

I want a button on my control panel, wired as a discrete input, to pause the current process. The feature is on the web interface. I hope the web pause button just uses one of the registers, in which case ladder logic fixes my problem. Can anyone tell me if I am correct? and if so, which register is it?

[JonW]

There are things that could be done to pause the process via a DIN, but the problem I see with this is that there is no such thing as a "current process". All processes run concurrently, so a single DIN is not going to be able to act upon a "current" process. You'll need to use a specific DIN for a specific process, or use a single DIN for multiple processes if they are not running concurrently - otherwise they would each pause.

The only way I could see doing this is to check for the DIN in each state, then move to another state (a pseudo pause) to stop the current processing. You would then jump back to which ever state you needed to in order to resume. This is not a pause feature in the registers or the ladder logic. You'd need your own paused state.

I do something a little similar with my fermenter. Because I don't want to have to pull up the web interface to start it or change from fermentation temp to crash cool temp, I just defined multiple states and use an On-Off-On switch wired into two DIN's to select states. When the process starts, State0 just sits and waits until one of the DIN's is asserted. It then jumps to either the fermentation state (State1) or the crash cool state (State2). Exit conditions in those states jump it back to State0 anytime the DIN changes again.

[ssgross]

Sorry I mispoke. I meant I wanted a din to mimic the functionality of the pause button on the Web interface. I have never ran 2 processes at once and so always assumed the button was for the current process. I have used a state to pause in some instances like you suggested. is the pause button connected to a register?

[JonW]

No, the pause button is not connected to any register. As far as I know, there is no other way to call the pause function other than through the web UI or the API.