NI OPC Server for CompactDAQ - unreliable

[Tony_Dean]

Hi,

We have been using NI Compact Fieldpoint devices with the "National Instruements.OPCFieldPoint" OPC server for many years without a single failure. However, due to their obsolescence we have been forced to use CompactDAQ along with the "National Instruments.VariableEngine" OPC server. Since then we have had many occasions when the OPC server just stops communicating with the modules and the only way we have managed to restart it is to carry out module self-test in Application Explorer - even cycling the power does not help! This has happened on all three of our installations at different times. Has anyone else experienced this and have a resolution?

Thanks,

Tony

[NataliaS]

Hello Tony,

Do you have any error message when the crash/hang happens? - Could you paste a screen shot of it?

Could you tell me more regarding the hardware you have in the system - an overview? How is it connected?

Lastly, can you elaborate more what you mean by 3 out of 4 installations? Does the error occur after isntallation as well? Have you managed to complete the installations?

Looking forward to hearing back from you,

Kind Regards,

Natalia 

[Tony_Dean]

Thanks for the reply. There is no error message, the OPC server continues to run but all channels return zero. In MAX, all modules have a red 'X' next to them which can only be cleared by performing a self-test in MAX. We currently have 3 installations which all use an Ethernet chassis but each installation has a different line-up of Compact DAQ modules. Everything works OK most of the time - the problem occurs randomly after a few weeks (or months) of operation. All of the installations have failed with the same issue a number of times over the past year. Because there are no errors, the fault can go un-noticed, leading to missing data.

Hope this helps, let me know if you need any further information.

[NataliaS]

Hey Tony,

Thank you for your reply, let's try to see whether we can distinguish if it is the client or the server side causing troubles. We can do this by trying different client/servers. I have a link that can guide you

http://www.ni.com/tutorial/2918/en/

If you have already tried those steps let me know what was the result

Kind Regards,

-Natalia

[Tony_Dean]

Hi,

I don't think its a client problem. We have two different OPC client applications and both of these see the same effect. Also, both of these clients are connected to the "National Instruments.OPCFieldPoint" server (supplied with Compact Fieldpoint devices) and this has continued to run for several years without problem.

My impression (which may be wrong) is that the OPC server continues to communicate with the client but is no longer acquiring data from the Compact Fieldpoint devices.

Hope this helps.

Tony