Problems connecting data socket variables to the tag engine

[Philip Holoch]

I have LV 6.1 plus DSC. When I connect data socket values from a vi to the tag engine, I cannot read the value of the tag in another vi. The first vi, that is connected to the data socket server is running, but I cannot read the tag value, not even with the tag monitor. I defined the DS value as publish and the tag as input only.
Can anybody help me on this problem ?

Thanks,

Philip Holoch

[Roli]

Philip,

I run today again into the same problem, we have seen earlier. If you use dynamically datasocket items in a VI and you publish and subscribe those items, everything should be fine.
However if now another VI with the LabVIEW DSC Engine's Tag would connect to one of those dynamically created datasocket items it would fail. (You should see in the syslog of the DSC Engine an error like: ERROR 04/23/2002 05:35:39 PM Server ERROR from Server: DataSocket. Server Message: Error: Can't connect to data item, another write connection exists.
ITEM dstp://localhost/samplenum)
The dynamic Datasocket items does not allow to set the published item to be multi-writeable. Thus whoever publisher subscribes first to the item will have write 'access'.
The only workar
ound for this problem would be to create a static datasocket item in the DataSocket Server Manager and enable the 'Allow Multiple Writers'.

Another problem might be on your system could be related to the registration of your current datasocket server. I've seen once on my computer with different versions of LabVIEW (6.0 and 6.1) that the registration of Datasocket was somehow damaged. And in this case, I could not read as well the tag in DSC (Input Only) when I write to the datasocket server with a regular DS Write VI. When I manually re-registered the nids.dll everything was working again.
If you go to Start>>Run and type regsvr32 c:\winnt\system32\nids.dll (or similar) it should re-register the datasocket automation interface.

I hope one of those two hints would solve your problem

Roland

[Philip Holoch]

Thank you, that helped.
It was not the dll registration. I had to declare the item in the data socket server manager and to allow multiple writers (even so I had a Input Only Tag before).