OPC DA/UA - Modbus

a screenshot of OPC server on PIPER Interface


In industrial communications, there are essentially two essential conditions that technologies must adapt to provide interoperability and security standard. One must guarantee that a protocol can communicate with any device or application and the other must ensure that a message is not distorted between the sender and the receiver.


It is seen as the group of standardized industrial communication protocols between devices and systems. Interoperability standard that software interface is implemented in a server / client type architecture, in addition to allowing the secure and reliable exchange of data between Windows programs and industrial hardware devices. The OPC server is a program that translates the hardware communication protocol used by a PLC. Connect any OPC server or client to other applications, including Excel, a web browser, or any other database.

logo of OPC interface service
flowchart of OPC features

OPC-DA (Data Access)

Gives the possibility of having data in real time, historical processes can be recovered for analysis, unlike other industrial standards, it has a reduced hardware load and its scalability of its system is greater thanks to the server OPC.

OPC Unified Architecture (UA)

Incorporates all the benefits of Data Access (DA) and adapts to current industry 4.0 communications. That is, it can be implemented on any operating system, be it Android, Linux or Windows. In addition, its security is based on encrypting communications through security certificates. Unified Architecture solves the problem of communication between real time, history and events, to have them in a single technology.


It’s an open communication protocol used to transfer data between electronic devices over serial networks. The device that requests data is called a Modbus master and the devices that transmit data are Modbus slaves (Server/Client). It is a particularly popular protocol in the industry, and this is basically due to two reasons: on the one hand, its proven reliability and, on the other, its free nature, which allows device manufacturers to use it independently.

Modbus logo