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DOPC is a light-weight Delphi library for easily implementing OPC-DA servers. Since the OPC-DA API is quite elaborate, DOPC makes some assumptions. For example, deadbands and access paths are not used. Also, a flat namespace is assumed. In other words, you might need to make changes to some of the underlying classes, but for most cases you won't need to.
To implement an OPC-DA server using DOPC, you need to do the following:
1. Create a type library with two interfaces: IDA2 and IOPCGroup.
2. Create a subclass of TOPCGroup, which also implements IOPCGroup.
3. Create a subclass of TDA2 which also implements IDA2, and override four methods: createGroup, findProxy, fillRefList and checkItemRef.
4. call registerOPCServer with the right classes and interfaces.
5. periodically call scanOPCServers.
The source code is more or less self-describing. The example application shows a very basic OPC server working. This code is very new and largely untested. Use at your own risk.
To implement an OPC-DA server using DOPC, you need to do the following:
1. Create a type library with two interfaces: IDA2 and IOPCGroup.
2. Create a subclass of TOPCGroup, which also implements IOPCGroup.
3. Create a subclass of TDA2 which also implements IDA2, and override four methods: createGroup, findProxy, fillRefList and checkItemRef.
4. call registerOPCServer with the right classes and interfaces.
5. periodically call scanOPCServers.
The source code is more or less self-describing. The example application shows a very basic OPC server working. This code is very new and largely untested. Use at your own risk.