USB VGA/Audio Cat 5 KVM Extender The CE750A is a USB-based KVM Extender with automatic signal compensation and RS-232 serial functionality that allows access to a computer system from a remote USB console (USB keyboard, monitor, and USB mouse). The CE750A improves on previous designs by the addition of an RS-232 port, on both the Local and Remote Units, that allows you to connect to a serial terminal for configuration (Local Unit) or serial devices such as touchscreens and barcode scanners (Remote Unit).