Thank you very much for your reply, YatinM.
I have seen both of these KB articles.
My problem involves writing to tags (via the datasocket).
E.G. I have a button on the front panel of a VI. The datasocket connection is pointed at tag 'x' and is configured to publish.
tag 'x' is configured in the DSC as a write only tag.
Other parts of the system are a Siemens S7 PLC and another PC which runs a simulation package (test stand). All items are
networked with a Siemens OPC server.
If the front panel of the VI is running and the button is toggled, the change in status is almost immediate (in the DSC tag
monitor). If the simulation package is started, toggling the VI front panel button does not result in a rapid change in status when
the DSC tag monitor is viewed - it can take several minutes for the status to change ! If the simulation package is stopped,
performance returns to normal (i.e. updating is rapid).
I did consider that the tag was being overwritten by the simulator via the OPC server, but this particular tag is not configured
on the simulator and as a "belts and braces" exercise, I changed the datasocket connection for the tag to publish and changed
the tag itself to write only (see above). In any case, once the tag state changes to match the state of the button, it does not vary.
The property node for the tag is in a while loop on the VI block diagram. If a probe is placed on the block diagram, it can be seen that
when the front panel button is pressed, the property node immediately assumes the button status regardless of whether the simulator
is running or not. The while loop executes at 250mS intervals - this has also been monitored and does not vary.
I have this problem with several buttons on several VI front panels.
I'm tearing my hair out and would welcome any further suggestions !!
Mark Last
