Multiple clients on StdAuto DNP I/O server


Thread Starter

D Holt

Two Wonderware Intouch clients connecting to one Standard Automation DNP I/O server via SuiteLink on NT4.0sp6a Servers. DNP server is running on the same system as one of the Intouch clients.

Anyone have any experience with a similar setup? We're having reoccurring problems with seemingly random points returning correct values to one client and "frozen" values to the other client.
Our setup is slightly different, We have a number of sites that use our DNP OPC Servers in a redundancy mode successfully. Each Intouch system can switch between the local or backup remote DNP OPC Server. Each DNP OPC Server also have redundant TCP/IP links to the RTU. We have no reports of Intouch clients getting inconsistent data.

[email protected]
I did a project recently where I had a Scada and InTouch communicating over DNP3.0. Had a tremendous amount of trouble. Final analysis was that Standard Automation DNP driver only supported a limited set of functions and the Scada was requesting an unsupported function (but a legal DNP3.0 function) Suggest you research DNP protocol. The DNP users group website is a good place to start

Jon S

Michael R. Batchelor

Which client gets "frozen"? The remote, the local, or random? The one with the server running locally should probably change to dde instead of SuiteLink. I've always found it to work better on the local machine. The NT IP stack doesn't come into play that way.

On the frozen machine, does *EVERYTHING* get frozen, or only some

We initially had some problems with protocol related issues which were solved by setting select-before-operate on our control points each time the DNP server is initialized and the DNP server seems to be polling the data from the RTU.

Our problem now is that two View nodes acting as clients to the DNP server will, at random times, retrieved different values for some points. Perhaps "different" isn't the best description. One client will display a flat-line trend for the same point that the other client will show a normal trend.

Only some values freeze and we've seen it happen on both clients. It isn't a total lockup of the client, just some of the display values do not change in one of the clients.

We've seen the display value for a tank level flat line on the View node running on the same system as the DNP server while the all other points in the same RTU continue to trend normally while the same point on the View node running on another system (getting its data from the same DNP server) display the correct values. We've also seen the points flat-line on the View node that is not running on the same system as the DNP server while they continue to trend normally on the system where the DNP is running.

We were advised by StdAuto to use SuiteLink as they felt it was more reliable than DDE.

If you are still having issues, we now have a server that was built based on request from previous Standard Auto customers. You may vist the site or email us if you have any questions for us. We support OPC, DDE, Suitelink, and FastDDE.