Importance and definition of remote I/O

Remote I/O, or RIO, short for remote input/output, is a system with which various sensors and actuators can be connected at decentralised locations within a plant or network and their data can be managed via a central controller. Nowadays, remote I/O is an essential part of modern automation solutions, as it supports the flexible integration and scalable expansion of automation networks. This is particularly important in complex industrial environments in order to efficiently manage all the necessary processes. By integrating remote I/O, industrial control systems can be changed and extended more flexibly without the need to make major changes to infrastructure. By using remote I/O, companies can reduce their operating costs, increase efficiency and simplify maintenance. Close cooperation with central control units and communication protocols such as PROFINET, EtherCAT® or Ethernet/IP is crucial for reliable data transfer and system performance.

How remote I/O works:

• I/O modules: these modules record the signals from sensors (e.g. temperature or pressure sensors) and control actuators (e.g. valves, motors). There are different types of I/O modules, including analogue and digital, depending on the type of signals that have to be processed.
• Communication interface: the recorded signals are transmitted via a communication interface (e.g. PROFINET, EtherCAT® or Ethernet/IP) to the central controller, e.g. a PLC (programmable logic controller). This interface enables bidirectional communication between the remote I/O modules and the central controller.
• Bus coupler: the bus coupler connects the I/O modules to the industrial network. It handles communication between the individual modules and the central control unit.

What is the difference between local and remote I/O?

A local or central I/O is installed in the control cabinet together with the PLC. A remote I/O, on the other hand, is decentralised and installed separately from the control unit.

The choice between deciding on a local I/O or remote I/O depends heavily on the individual requirements and framework conditions of an application, e.g. a centralised architecture may make sense in smaller systems, while larger, more complex networks may benefit from the strong points of a decentralised structure. Another aspect that companies should consider is compatibility and integration with existing controller systems to guarantee seamless and efficient implementation.

What is decentralised I/O?

Decentralised I/O is a remote I/O system with a predefined number of inputs and outputs. It is a self-contained unit and cannot be expanded.