The Crestron® CEN-CI3-3 is a single-space rack-mountable device designed to provide a versatile control interface and expansion solution using up to three 3-Series® Control Cards. 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 placed on a shelf or rack-mounted using the rack ears included. It interfaces with the control system via Ethernet.

The CEN-CI3-3 accepts three 3-Series control cards (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.^[1]