OPC Comm. with a NI PCI-FBUS/2

[GerryM]

I lose communications intermittenly between my VB.net program and the NI-OPC Server.  (Once per week)

It occurs after a long period of no use by the operator, usually overnight.  The program and network is always active 24 hours a day.  Only a screen saver is used during periods of no use.

I use the auto update feature in the OPC Client.  I changed my program to force a read of the OPC Group that communicates with network #2 every 10 min., and the problem reduced in frequency from once per week to once per two months.

It happens always on network #2, which consists of three 3051S Rosemount Pressure Transmitters.

It recovers by simply opening the NI Configurator and viewing my FF configuration.

Something seems to be falling asleep, I assume it is the OPC Server, and the configurator wakes it up.

Other than that everything has been excellent.

[fieldbus]

Are you using NI-FBUS CM 3.1 (or later) version? If so, the NI-FBUS OPC server should be OK. But the continuous auto updating with long time might result communication failures sometime during a heavy network traffic period. And continuous failures might cause OPC server stop to respond.  But the Configurator has better recovery mechanism to deal with communication failures. I guess that's why launching Configurator helps on your problem.

It's good to have NI-FBUS Monitor running in the H1 network during the problem occured, which helps to judge whether it is causd by communication failure.

You can also send e-mail to fieldbus.support@ni.com with detailed description about your problem, maybe there is other solution on your problem.

[GerryM]

Thanks for the reply!

I do have v3.1.  I noticed there is another minor upgrade which i will try.

I will probably have to play around and see if I can build my own fault recovery routine.  It has just been a little difficult to learn the ins and outs of this problem since it is so intermittent.

Thanks again!

Gerry

[fieldbus]

The 3.1.1 version is the latest version with some improvement of 3.1 version, hopefully this 3.1.1 version helps on your problem. If it still doesn't help, please send e-mail to fieldbus.support@ni.com for support.

[GerryM]

I have now upgraded to the latest software, and the problem has not changed.  I am now logging all bad values to a text file.  And for some reason, the values will all of the sudden go to zero with a quality value of zero.  I am reading four sensors.  It starts with any one of them, and a while later spreads to all of them.  This happens every day.  The problem happens on both channels.

To recover, I need to shut down the opc server and restart it.  Opening the configurator doesn't seem to affect it as it had once before.

Why would the OPC Server suddenly read zero values?

[GerryM]

Please ignore my last message, I made a mistake. 

I'll repost later with the correct information.