I/O Relay Module RacksI/O (input/output) relay module racks are devices that are used to organize and manage a large number of relay modules in a single location. Relay modules are electrically operated switches that are used to control the flow of electricity in a circuit. I/O relay module racks provide a convenient way to mount and connect multiple relay modules in a compact and organized manner. They typically consist of a rack or frame with slots or openings for the relay modules, as well as connectors and wiring for connecting the modules to other devices in the circuit. I/O relay module racks are commonly used in industrial automation and control systems, where a large number of relays are needed to control various processes and equipment.