Distributed I/O

Distributed I/O refers to input and output modules placed close to field devices rather than centralised in a main control cabinet, connected to the controller over an industrial network. This reduces wiring runs by gathering local signals and transmitting them digitally back to the controller.

With distributed I/O, remote modules near machines or sensors handle local signal connections, then communicate over a fieldbus or industrial Ethernet to the PLC or PAC. This shortens analog wiring, simplifies installation, and eases expansion. Distributed I/O matters because large plants and sprawling machines would otherwise require enormous cable bundles to a central panel; placing I/O at the point of use cuts cost, improves diagnostics, and makes systems more modular and serviceable.