We recently converted from RS3 to DeltaV. During the temporary switch over we immediately encountered Bad PV Alarms on Analog and RTD measurements. The RTDs are RTDs not transmitters. We knew we had a couple grounding issues to resolve... but after the permanent switch over, resolution to all grounding procedures and plant startup... the Bad PVs are back. Same wiring, same instruments as with the RS3 system. We didn't have this problem with the RS3 though. We'll get hundreds of these alarms a day. They're now suppressed but are filling the event logger. Blocks are configured to switch to manual during the Bad status and then return to previous state. So... we're working around it, but need to solve it. Am wondering if it's software issue, i.e. software misses the read and sets the Bad PV. Any ideas? Thanks folks!

 

I have had these errors in my DeltaV system before, however the Bad Pv has been do to either a bad card, terminal block or a open circuit to the x-mitter. I'm wondering if the voltage on your RTD circuit is so low that the Delta V interprets this as an open circuit? Just an idea, good luck.

 

We have the same problem with analogic input on Profibus. PV_BAD_Alarm and General IO Failure? If you have an idea, there will be great!

Many thanks
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