Hello All -
I'm having a problem interacting with my OPC server, and I'm hoping some suggestions will help me out here.
I have an OPC server running on a XP SP2 machine, and it is interacting properly with my equipment (a bioreactor). When I use the NI OPC Quick Client, I can browse to the tags I want to see, and those tags update as expected. I can put my hands on the temperature sensor and watch the output change on the QuickClient screen. The only odd thing that I have to do with the Quick Client is that I have to manually set the data type (Float, Single, Double, etc.) and request an asynchronous read before it will begin updating.
When I try to connect via Shared Variables, it's a different story. I create the shared variable using the instructions at the bottom of this page:
http://digital.ni.com/public.nsf/allkb/EA15F53DB6FECCA5862567240064DF09
Next, I drag the variable to my front panel and start the VI. A summary of the behavior is this:
* As long as the variable type is read/write, the LED is green on the VI.
* I can write values to the OPC server
* The VI never shows data arriving from the OPC server, I can only write.
* No error messages are received.
This behavior doesn't change for any permutation of "read/write" status in the variable definition, switching the node from read to write, changing the control from read to write, etc.
I'm using Labview Developer Suite 8.6 with the DCS option. Fresh install of Windows and LV. No other software on the machine.
Any ideas how to troubleshoot this? I'm running out of ideas...
One other update, which may or may not be related: Whenever I try to connect using a DataSocket method via one of the example VIs such as "Monitor Multiple OPC items.vi", LabView crashes immediately.
Message Edited by wdmarner on 10-06-2008 10:56 AM
Message Edited by wdmarner on 10-06-2008 10:57 AM
