How 800xA OPC Client Connection Licensing Work?
We have delivered 2 systems, one with 800xA OPC Client Connection license and the other one without 800xA OPC Client Connection license. But both system can communicate with 3rd party system with DCOM configured (ABB.AfwOPCDASurrogate) read/write value wihtout any problem. Until last month there was incident when customer restart one OPC server on the system without license 800xA OPC Client Connection, all objects that communicated to 3rd party change to default parameter(AIC, DOC, DIC, AOC, AI, AO, DO, DI, etc). Is this the effect of the system running without 800xA OPC Client Connection license?
Asked 4 months ago
Answers
1
First of all, DCOM Setting to subscribe OPC DA Surrogate of ABB OPC Service is not a recommended way for OPC Communication. If you are going to run the OPC server on one PC and the OPC client on another PC, the settings required for DCOM must be performed on the OPC Server PC.Various problems may occur if an OPC Client, running on another PC than the OPC Server, is stopped abruptly (if, for example, the network between the OPC Client and Server is disconnected).
When installing OPC Server on any workstation, then that workstation is directly subscribed to the OPC DA Service from the controller and not from any other Workstation using DCOM. The third party OPC client shall reside in the same workstation and fetch the data from the server. Additionally, if you check "Save Cold Retain Values" option in the OPC Server installed in that workstation then you can retain values of all parameters.
When installing OPC Server on any workstation, then that workstation is directly subscribed to the OPC DA Service from the controller and not from any other Workstation using DCOM. The third party OPC client shall reside in the same workstation and fetch the data from the server. Additionally, if you check "Save Cold Retain Values" option in the OPC Server installed in that workstation then you can retain values of all parameters.
Answered 4 months ago
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