The Crestron® CEN-CI3-1 is a compact device designed to provide a versatile control interface and expansion solution using any single 3-Series® Control Card. It is used to expand the control ports of a 3-Series Control System®, and can be installed with the control system at the central equipment cabinet or located remotely near the device(s) under control. It can be rack-mounted, placed on a shelf, or attached under a table.^[1] It interfaces with the control system via Ethernet and can be powered via PoE or a dedicated 24V power pack.^[2]

The CEN-CI3-1 accepts one 3-Series control card (sold separately). Control cards are available to support bidirectional RS-232, 422, or 485; IR or 1-way serial; 0-10V analog inputs; digital logic inputs or outputs; and low-voltage relay outputs.^[3]