Fisher DVC 6000 SERIES PWB COMMUNICATION FAILURE WITH DCS

[Kiran369]

I am working with reliance and in our plant we are facing frequent PWB POWER RESET issues in DVC 6000 series positioners. During this power RESET positioner will stop communicating with DCS. We are not exactly getting the root cause why this PWB is going into power RESET mode and why it's stopping communicating with DCS. Looking forward for proper solution and guidance and the same highly appreciated.

 

[danw2]

I have no experience with that positioner, but if I were troubleshooting this, I'd start with asking the manufacturer if they're aware of an issue, because when multiple devices of the same model have the same problem, it's a fair assumption that they're likely the same age, many times the same production lot. So it's worth asking the manufacturer about any firmware or production issues from that era, supported by a list of the model/serial numbers to establish the dates of production.

And I while I was asking the factory guy about production issues, I'd ask what PWB POWER RESET means (if it's a positioner error code, it could be host system error code, you don't say). It sounds to me like it means a loss of power and subsequent re-initialization of the unit, but I'm speculating, and it helps in troubleshooting to know exactly what the error code means. If it is a host system error code, what are the error codes the positioners have logged?

Once I'd ruled out a common-mode 'vendor' problem, I'd add a couple columns to my model/serial number spreadsheet with tag locations and times/dates of failure and look for a pattern.

When something happens to multiple positioners the question is, what do these multiple positioners have in common?
Same AO card? Same DC power supply? Same remote terminal panel in the marshalling panel?

Do the times and dates of failure show any pattern, like Monday morning at 6AM sharp 3 of them drop out, same time when the auxiliary compressor starts up?