Server Client Disconnected, Why QC Hold last good Value as Bad Quality?

[BRangi]

Hello Team,

We are having Two Kepware for tunneling OPC DA to UA. First Kepware is installed Locally with OPC DA server in source, Second one is in L2 system to connect first Kepware as OPC UA client.

Issue is whenever OPC DA server or OPC UA server got disconnected  from source with L2 Kepware, it's Quick Client hold the last good Value with quality Bad. As soon we open new QC it shows unknown value.

Can you please explain me about this phenomenal?  If you do any have whitepaper please share with us. 

Due to this above issue, MES captured the last hold  bad Values from L2. 

[cmorehead · Accepted solution]

@BRangi 

The default behavior for a failed read is to persist the last known value but notify the client that the quality is bad. The timestamp sent in the client notification shows when the read attempt (poll) was completed but failed. Here is a link to a work-around using Link tags:

Article - CS341670 - Setting a dead value in Link Tags for PTC Kepware products

I also recommend opening a support ticket with the Kepware team if assistance is needed in setting up the work-around.

Thanks,

*Chris
 

[BRangi]

Hello @cmorehead ,

Thank you for the information. I'll refer this article and if require I'll open case. 

BR,

Bhadresh