As you probably know, the OPC standard was created in order to standardize the communications between two or more devices using different communication protocols. Indeed, thanks to the OPC standard these communications can be established in a fully transparent, which is the very principle of interoperability.
Today, the old version of the OPC standard, namely the OPC Classic, is in the process of being completely replaced by the OPC UA or OPC Unified Architecture. With industry 4.0 and the industrial Internet of objects, the OPC UA standard is becoming the communication standard of choice for most manufacturers, ranging from PLC manufacturers to manufacturers of on-board electronic systems.
Access, collection and management of data is fundamental to any modern control system, but it has traditionally been expensive and difficult to obtain. Businesses are increasingly moving away from proprietary systems and looking for robust and open solutions, in order to manage and analyze data in a manner adapted to their existing IT systems (ERP, MES etc.).
Indeed, the OPC UA standard is a real revolution:
- With the OPC UA standard, we no longer have to deal with COM / DCOM components because the OPC UA is based on Web services
- OPC UA is more secure with the integration of authentication and encryption systems
- OPC UA is multiplatform (not linked to a specific operating system)
Thanks to all these characteristics, the OPC UA is increasingly adopted for the collection and sending of data to the Cloud, for example for predictive maintenance applications requiring the acquisition of field data and its exploitation via solutions. Since the OPC UA uses Ethernet, any physical layer (including wired, wireless, cellular, and satellite) can be used to communicate through OPC UA.
How to create an OPC UA client?
To create an OPC UA client, used for example to communicate with a PLC, you will need an OPC UA stack. As an open source OPC UA stack, we have for example FreeOpcUa. FreeOpcUa is composed of a C ++ library allowing to develop OPC-UA server and client applications in C ++ language. FreeOpcUa also includes a Python library which allows you to create OPC UA servers / clients in Python language.