Issue
Clarification regarding Vista's OPC server and OPC client functionality. Incorrect configuration can cause unexpected results and crash the system.
Product Line
TAC Vista
Environment
- Vista Server
- Vista OPC Server
Cause
There is some confusion as to the usage of the OPC server object in TAC Vista workstation.
Resolution
TAC Vista OPC Server
TAC Vista OPC Server is an add-on module to TAC Vista Server, which enables third party OPC-compliant presentation systems to interface with TAC products. All objects and signals in the TAC Vista Server database can be read and changed via the OPC Data Access interface. Vista OPC Server is implemented as a Windows service and can be started from the Computer Management console.
A license is required, but no configuration is necessary in workstation
TAC Vista OPC Client
The TAC Vista database has to be programmed and configured as an OPC client, using the TAC Vista OPCTool. Simply browse the available OPC servers, select the objects to be added to TAC Vista and then from the tools menu select "Create/update TAC Vista objects...". When the dialogue opens up, browse to the appropriate location and select the OPC server object to be updated. If this is a new OPC client, right-click in the dialogue and select New->Device-OPC server. The object's properties will then be set by OPC tool after clicking on the select button.
!!Do not create an OPC server object in Vista and set the program ID to TACOS.OPCServices.DA.1 and the Class ID to {7EA83597-0B54-4BAF-9EE5-D30AA9EB4D6D}. This will create a loop in the system and cause unexpected behaviour. There should be no OPC server objects in Workstation if TAC Vista is the OPC server!!
