OPC DA Server Toolkit - Features
- DLL-based, object-oriented toolkit. Easy to update as standards evolve and new features are introduced.
- Designed for creating out of process, local and remote servers using MS Visual C++.
- Includes sample simulation server and reference implementation source code for MFC-based and ATL-based OPC servers.
- OPC private security support, for controlling access to server data.
- Detailed reference manual included.
- Multi-language support for server error messages.
- Can be used with the Northern Dynamic Alarms & Events Server Toolkit to create an integrated DA and A&E OPC server.
- Binary and source code licenses available
A sample simulation server and a test client application are installed with the toolkit demo software. Sample source code is also included for MFC and ATL-based server implementations.
How It Works
How the OPC DA Server Toolkit Works
The OPC DA Server Toolkit is a DLL that you link with your application. Your application may be a new or existing application to which you want to add OPC DA compliant interfaces.
The DLL exposes a simple set of objects and API calls behind which are aggregated all the COM interfaces and OPC object resources required to manage OPC DA client connections.
The diagram illustrates the toolkit objects (in blue) used by a developer. The OPC DA server objects (in red) are automatically managed by the toolkit. You write the code that integrates the toolkit callback object with your system’s interfaces and that creates a shared data cache.
What the Developer Does
As the developer, you work with the toolkit objects and API calls to provide the following.
- Manage (create / delete) items in the data cache using the a base class supplied by the toolkit. Your cache can be static or dynamic.
- Whenever the underlying value or quality for a cache item changes, update that information in the cache.
- When an OPC client requests or modifies a specific update rate for an OPC group, verify your underlying system can satisfy this request, otherwise return a rate that can be supported.
- Manage the namespace of your server in support of OPC browsing. The toolkit provides sample code and helper classes to assist with implementation of browse support. The helper classes work in conjunction with the CTKBrowser object exposed by the toolkit.
- When requested by the toolkit, perform device reads or device writes.
What the Toolkit Does For Your Application
Here is a summary of what the toolkit does for your application.
- Manages all OPC DA client connections for your server.
- Efficiently creates, manages, and destroys OPC DA COM objects as required.
- Transparently manages OPC groups (and the OPC items therein) created by an OPC DA client.
- Synchronous and asynchronous reads from the data cache are automatically handled by the toolkit.
- Utilizes the COM free threaded model for optimum performance.
- Designed to handle the transfer of thousands of items per second.
Three-Tiered Diagnostics Suite
The toolkit supports a three-tiered set of diagnostic tools. The built-in tools can be used by your technical and field support personnel to quickly resolve client-server integration problems. See the data sheet for a detailed description.
- Tier 1 - Client Connection Statistics
- Tier 2 - Client-Server Trace Logging (more...)
- Tier 3 - OPC COM Call Tracing (more...)