I do have a problems with settings of DCOM / NI-OPC server / shared variables etc. I have done so far the following to get the correct SV response:
1. setup OPC server(demo poject settings), allow remote access where ever I could
2. setup in "DCOM config" sectuion (in dcomcnfg) "OPC server 2012", then DCOM enable users INTERAKTIV / EVERYONE all access - remote access as well
3. enable the firewall exeptions for all related softwares (even OPCenum.exe)
4. give local admin rights for every related user
5. re-booted several times
I am able to see/select in "Create Bound Variables..." the certain variables, but not able to read it in Labview. Also not able to read / monitor in "Distributed system manager 2012"
See attached foto.
I have installed locally NI OPC-server as well, there is no problem to access all variables.
All answares are appreciated.
Thank you very much Paolo!
I forgot to mention that it is working with datasocket read (with URL address), but response time is a bit high(500 - 2500 ms) and fluctuating. I'd rather use Shared variables. As It can be seen on the picture the variables existing - can be bounded - but during run I got no real values. Why it is like this I do not understand and only in remote mode. Locally it has no problem. I have also tried the "NI variables" service to configure other user but no success at all.
I was also monitoring if the OPC server shows a client connection during my VI is runnign but no. If I do the bounding the variables the OPC Data client will appear, but durign run the number of connection is 0.
i found this error description:
This warning will occur if the shared variable is bound to a source, but the variable has not received a value from the source. This is only a problem if the variable never receives an update from the source, even if you are sure the source is generating updated values. In most cases you can ignore this warning.
Maybe the following link can help you
You can dramatically improve DataSocket read speed by using DataSocket Open once (at application start) and passing the Connection ID to the Read function instead of the full URL.
I saw also this acticle, obviously: first thing to check what is the error cause...
The problem is basically I NEVER got any other value then "0". This was the problem. Also was able to see that "Connected?" variable always FALSE. So even the SVs are correctly bounded was not able to read correct values.
I have tried to play with DCOM settings and from the same domain I was albe to connect to the Shared variables, here also comes sometimes the warning code -1950679034, but not all the time.
To those have same problems some hints briefly:
All "OPC"- or "NI"-related DCOM-configuration must be enabled for INTERACTIVE and EVERYONE (add these users in dcomcnfg.exe), where possible on "Identity tab" set Interactive user.
This should be done on SERVER and CLIENT side as well.
First turn off the whole Firewall to check if able to connect NIOPC.V5. Later the Firewall can be fine-tuned.