The Control In port of the UCM is where serial port data from a PC is accepted. The Control In port can either be left unused or it can be used for serial communications control of the matrix. Serial control can be established using any UCM, including remotes.

All operations of the matrix can be controlled from the UCM Control In port which is typically connected to a PC. The connector is configurable and can communicate in one of three serial interface standards: RS‑232, RS‑422, and RS‑485. Software configuration is covered later in the Serial Interface Menu section of this manual.