Hardly a groundbreaking revelation but sometimes we need to be reminded of that fact.   Since OPC is a standard interface, and all OPC servers are implemented against the same specification, people tend to extrapolate that to mean all Servers are the same.  We know this is not true, since there are many other things to consider when selecting the right OPC server (or any software for that matter).

Software Quality is one consideration.  Security is another.  Dale touched on these topics on the Digital Bond blog.  (This is, of course where I got the inspiration for my topic.)  Other product considerations are device specific features.   These could include things like auto configuration, item management or redundancy support.    How robust is the product in terms of error handling and logging problems?  How user friendly are the interfaces?   The OPC specifications can only specify so much and many things other than compliance that separate one OPC vendors’ products from another.   Not to take anything away from Certification.  In fact, OPC Certification should be the FIRST thing you look for in an OPC product.   

I suppose the full quote would be “All OPC Servers are not created equal but should be treated as though they were under Compliance Testing”.   The paramount goal of OPC is interoperability.   The OPC Foundation Certification process is designed to ensure that when a user creates an architecture with OPC products from multiple vendors that it will work.  In a perfect world that would be the base starting point for all OPC products.   Those things beyond interoperability are in the hands of the OPC vendor and this is what makes them stand out in the crowd.

So take some time in determining which OPC product is right for you, and which vendor will offer you the services and support you need.  In the words of Napoleon Bonaparte:  “Take time to deliberate, but when the time for action has arrived, stop thinking and go in.”