Why are my Datasocket OPC reads and writes so slow?

[Sirin]

I am creating an application (in LabView 6.1) that has to interface with 15-30 OPC tags (about half and half read and write) on a KepWare OPC server. It seems like the DSC Module would be overkill, but the datasocket write VIs seem to slow the system to a halt at about 6 tags. I saw something about using the legacy datasocket connect VIs, but would I really see a large performance boost from switching?

In the existing code we have, I have seen that even the legacy VIs (our old code uses the older VIs) sometimes grind the system to a halt or lock it up completely if it loses sight of the OPC server. Has anyone else had problems with this?

[Balze]

Hi Sirin,
i had some trouble with datasocket aswell.

Most trouble occurred, if the link to the OPC Server wasn't stable.
Did you try to connect your Items using a Control/Indicator and the "Data Socket Connection" ?
(right click - data operations - Data Socket Connection - browse - "select your item")
You'll receive a connection Indicator to see if your connection is stable.

Rainer

[Sirin]

We're using the 'datasocket open' VI to open all of our tags (using a for loop) at the beginning of the program. I've seen performance issues doing it through controls though as well. How did you resolve your issues with datasocket? Or did your programs just always crawl if you didn't have a good connection to the OPC Server?

[Balze]

Right !
If the connection to the OPC Server terminates, the application is extremely slow.
Try to view your items using the control method to verify your connection to your OPC server.

Rainer

[Sirin]

control methods?

[IYUS]

I got this problem as well. Although OPC server is localhost.
I am using LV 8.0.

[Spex]

Hi IYUS,

What OPC Server are you using?  What methods are you using to communicate?  If you are using IAOPC, have you installed the latest patch?

Also, this post is nearly 2 years old.  You will probably get more visibility (and more help) if you post your questions in a new thread.

Cheers,