What is OPC-DA?
OPC-DA stands for Open Platform Communications Data Access – this is a communications protocol used for accessing process data. OPC-DA was released in 1995 and since then has become extremely well known; popular to the point that these days, most SCADA system providers will support OPC-DA.
OPC-DA will retrieve data from a device while also providing a VQT (value, quality and timestamp), but it is worth mentioning the dated nature of OPC-DA means that it is not OS agnostic – and is in fact, almost exclusively a windows product.
What's the difference between OPC-DA and OPC-UA?
OPC-DA comes under the OPC Classic model. OPC Classic uses DCOM communication for Client-Server connection. DCOM is for Windows OS. And, DCOM and RPC ports aren’t as engineer-friendly.
OPC-UA does not rely on DCOM communication and is operating system (OS) agnostic. As well as this OPC-UA has many more attributes/properties that can be shared between client and server.
For these reasons it is recommended that when a choice is available, OPC-UA is the better option.
OPC-DA, is an older version of OPC specification. It was built without security and firewalls in mind and has problems with authentication and security.
OPC-DA to MQTT adapter
The ability to take OPC-DA messages and transcribe them to MQTT is extremely useful because typically, these two communications protocols will not communicate with each other. OPC-DA will gather VQT data and pass that along. MQTT on the other hand is preferred by developers due to its ease of use, speed and user-friendliness.
To learn more and understand how our solution can fit into your system. Please get in touch with our team.