The IMP-S21U is an HDCP 2.2-compliant 4K at 60 HDMI switcher with four inputs and one output. Digital audio of selected input channel can be de-embedded to analog audio. The switcher also includes RS-232C and LAN as communication ports that offer remote setting from WEB browser or control commands. Additionally, contact inputs/tally outputs enable the IMP-S21U to be controlled from the PC I/O board and a control box.