Glossary · Industrial communication
Remote I/O
Also known as: Distributed I/O, Decentralized I/O, Remote I/O station
German: Dezentrale Peripherie
In industrial automation, remote I/O is input and output modules installed close to the sensors and actuators, away from the controller, and connected to it via a fieldbus or Industrial Ethernet instead of individual wires.
- Industrial communication
In one sentence
Remote I/O places input and output modules near sensors and actuators and connects them to the controller over a network.
Example
Each module of a long conveyor has an IP67 remote I/O block that collects the local sensors and sends their states to the central PLC over PROFINET.
How it applies
- Engineering: Remote I/O reduces cabling and cabinet size. Stations can be cabinet-mounted (IP20, DIN rail) or machine-mounted (IP67). The station acts as a device on the network; its modules form the I/O image.
- Commissioning: Module configuration in the controller must match the physical station. Loss of the station must be detected and handled by the control program.
- Safety: Safety I/O modules in remote stations transmit safety signals over safety protocols such as PROFIsafe or FSoE. The safety function remains the responsibility of the whole system design.
- Documentation: The documentation team shows station locations, module order and addresses, and describes behavior on communication loss (substitute values) and the module replacement procedure.
Remote I/O vs. remote access
Remote I/O is about where the I/O hardware sits. Remote access is about reaching a system from outside, for example for service. The German "dezentrale Peripherie" always means remote I/O.