What is meant by OPC & list the common ports used for OPC?

What is OPC?

  • OPC, is acronym of OLE for Process Control, is the name of a common communication interface used in automation engineering.

  • The software objects or apps that supply their capabilities to other applications are referred to as components.

OPC in Control system

  • An interoperability standard for the safe exchange of industrial automation data is called Open Platform Communications (OPC).
  • It is made to be platform-dependent so that gadgets from many suppliers can exchange data.


  • OLE (Object Linking and Embedding) is also known as OPC (Open Platform Communications) or OLE for Process Control.
  • It is an industrial automation protocol type.
  • In the Client/Server pair, the OPC is always utilised.
  • The PLC hardware communicated data is converted into OPC protocol by the OPC server.

OPC in Process Control

  • Open Platform Communications (OPC) is a group of industrial telecommunications standards and specifications. For process control, they are based on Object Linking and Embedding (OLE).
  • The initial standard, known as OLE for Process Control, was created in 1996 by an industrial automation task group.

Object Linking and Embedding for Process Control

  • OLE for Process Control (OPC) is a set of standards created by prominent industry supply firms with the goal of developing standard protocol extensively for data exchange between industrial control systems and other devices.
  • OPC is utilized to facilitate application integration, allowing for a high level of app compatibility.
  • Also, it makes it possible to create plug-and-play objects that may be reused and are interoperable with other program. It is a software platform that makes it possible for hardware, automation machines, and control devices to communicate with one another.

OPC in Variety of Ports OPC communicates using a variety of ports, including:

  1. TCP/IP port 135: The initial connection between OPC clients and servers takes place over this port.
  2. TCP/IP port 102: OPC clients and servers communicate over this port.
  3. TCP/IP port 44818: OPC-UA (Unified Architecture) communication takes place on this port.
  4. TCP/IP port 4840: OPC-DA (Data Access) communication takes place on this port.
  5. TCP/IP port 4841: OPC-HDA (Historical Data Access) communication takes place on this port.
  6. TCP/IP port 4842: OPC-AE (Alarms and Events) communication takes place on this port.

Applications and Standards for Process Control (OPC) Regardless of the software or equipment being used in the process, OPC offers a standard interface for communication between various process control devices. To achieve a common plug-and-play approach, Microsoft developed it in collaboration with other software firms. As all OPC drivers function in the same way, a device could readily connect to another and function without further configuration.

Complementary Object Model (COM)

  • Standard interfaces for data sharing and inter-component connections are provided by COM.
  • Applications can now leverage functionalities from any other application object or operating system thanks to COM.
  • Moreover, it enables software component upgrades without impairing overall operation.

Industrial Uses for OPC

  • OPC provides an open, impartial communication framework that makes it possible for third-party program to communicate with each other seamlessly.
  • llIt offers a secure network for businesses who need a convergent, end-to-end secure network connection thanks to its well-proven security features like authentication, authorization, and encryption.

OPC Interface

  • An OLE-based consistent and vendor-independent software interface is defined by the OPC interface definition.
  • The access methods of the communication networks of one manufacturer were previously the only options available to applications that access process data.
  • The standardized OPC interface currently enables a user to have uniform access to communication networks of any vendor via the OPC interface. For example, user might operate control and monitoring software.

OPC Specification

  • In addition to the data access definition, the OPC standard also offers additional standards for other aspects of automation engineering in Alarms & Events, Historical Data Access.