-=| Methods to monitor I/O status between SLC & HMI? |=-

We are using WonderWare as HMI, currently we are using a "STATUS" tag in WonderWare to monitor I/O status on channel 1 on the SLC 5/04. That's proving to create a nuisance alarm. I'm looking for another method to monitor I/O status. I've tried S:1/7 Comms Active, but it doesn't work the way I think it should work. Any suggestions would be great.

You want to monitor the channel status of channel zero?

The serial port comms active bit will go to zero after ten seconds of inactivity. It may also go to zero and seem to stay there depending on how you configure it and how it is connected to your HMI system.

For that reason, I would suggest you build a heartbeat signal.

Have the SLC examine a bit, and if it is ON, turn it off. Have Wonderware examine the same bit, and when it is off, turn it on.

Now you can program both the SLC and the wonderware system to set a fault if the bit does not change for x seconds.

I am not experienced with Wonderware, but I expect this to be possible.

Hope it helps,
Paul

Typically in all my wonderware dealings with AB I typically have done what OkiePC states in building a heartbeat counter to and from Wonderware. I'm assuming Wonderware is using DH+ to communicate to the SLC 5/04.

Thanks for the input. I'll try a heartbeat curcuit out, should work.