E_FAIL and Watchdog

Archived Topics
1

We are having some issues with communications between two buildings (about 1.5 miles apart). We would like to email when communications are bad (not the problem). To do this, there is a bit in Kepware called Error which shows up when, for example, the ethernet cable is unplugged from the PLC. There have been some cases, however, when this bit is not triggered. Basically, communications are bad, but Kepware doesn’t think it is bad.

The question:
We would like to set up a watchdog bit in FactorySQL to monitor if communications are down. When it goes down, even if Kepware doesn’t recognize it, the values on the bits read ‘E_FAIL’. Problem is, E_FAIL isn’t really a value, so we can’t set an action item for it (example, if(value=‘E_FAIL’,1,0) ). Is there some kind of an expression for a ‘compare’? Basically, if we set a bit in the PLC to go on and off every 2 seconds say, and FactorySQL doesn’t see that bit change at least every 5 seconds, or something like that, then go on alert and send an email.

Let me know if this doesn’t make any sense.

2

So even if kepware isn’t reporting an error, the value still goes to E_FAIL? Try this: double click on the OPC item (or a copy of it) and change the “Property” property from “Value” to “Quality”, and the datatype to Int. Now check to see if this goes from “good/192” to “bad” (or anything else) when there’s a problem. If so, you can just alert anytime this value doesn’t equal 192. Or you can do an int comparison in an action item.

If that doesn’t work we can go forward and try to figure out how to implement a watchdog timer like you asked for.

Regards,