We have a client that is reading values from the opc server continuously. After around 20 days the values stopped changing. When I did a demand read from the client application, the values still did not change. Once I added the tags again to the group they started changing.

The status of the opc item was good even if the values did not change which leads me to believe that the tags were existing in the opc server. Just thinking out loud, could it be that the opc server deactivated the tags in the group after a while? I am not sure why it did that and would appreciate any input. The client and the opc server are on the same machine which leads me to believe it is not a network issue. Could it be a COM issue? The opc server is on a windows 7 workstation. The opc server is run as an application not as a service. I also had the same connection via tunneler from a remote client and these tags stopped changing as well and the same pattern was observed.

 

Sounds most like a bug with the OPC server. Who is the vendor for the OPC server?

One could be able to check the 'enable' status of both the group and the item to see if either was disabled for updates.

One could also try disabling, then enabling, the OPC group and/or item to see if updates recover.

 

> Sounds most like a bug with the OPC server. Who is the vendor for the OPC server?

OPU S-B R U K E R. Is there anything in the register i can modify to keep the group alive?

 

How can i check the enable status? I am using matrikon opc explorer. I tried as well as de-activating and reactivating the tags and nothing happened.

 

Some times items will get orphaned or RPC will fail over over time. The first is typically a bug in the server the second is a bug in the OS.

A Quick test would be to force a synchronous read of the device from the client if you can.

Have you contacted the server manufacturer to see if they have any reported bugs.

 

> How can i check the enable status? I am using matrikon opc explorer. I tried as
> well as de-activating and reactivating the tags and nothing happened.

Update state is accessed by viewing and adjusting the checkbox within the properties for the group ("Enabled") and item ("Active").

If toggling the enabling did not work, perhaps use a different OPC client to check if it encounters the same problem. If the second client fails in the same manner, then there is an internal problem the OPC server which only its vendor can resolve.

 

I tried doing it (which is disable and enable the group) when it happened again but did not work. I also tried to do sync and did not update. When i polled the properties of the item nothing came back, as if the item that the client is connected is no longer there or the server is not acknowledging the client to provide the info.

 

Hello,

I have got very similar problem. In my configuration there is a WinCC OPC server and other computer is located AVReporter Energy Management software.

After that about 5 minutes logging stop, I don't what is the problem.

Exact configuration:

- WinCC 7.0 SP2 Update8

- AVReporter v3.0 R2 Energy Management Software (read about 15000 tags from WinCC)

I use OPC DA connection I used above settings:

http://www.konsys-international.com...g-opc-tag-from-wincc-7-x-to-avreporter.11734/

I am waiting idea, what is the problem.

Thanks