Some remote locations need more than a single control drop — but not a full processor. The KanexPro CR-EXPAND4 bridges the gap with four extended serial ports and four relay outputs in one compact Ethernet-connected box. The first two extended ports (COM 1–2) support RS-232, RS-485, and RS-422 with hardware flow control for bidirectional device communication, while COM 3 and 4 provide RS-232 with hardware flow. A dedicated MAIN COM uplink connects to your control processor or PC, and a NEXT COM output enables daisy-chaining multiple expanders. Four relay outputs handle motorized screens, lighting, blinds, and door locks — enough to automate an entire satellite room from one device.Designed for boardroom satellites, multi-device closets, classroom hubs, and backstage control, the CR-EXPAND4 connects to your control processor over 100M Ethernet using standard TCP/IP and UDP protocols. Front panel LEDs provide real-time status for power, LAN, all four relay channels, and TX/RX activity on every serial port — making on-site commissioning and troubleshooting fast. Where the CR-EXPAND1 serves single-device remote drops, the CR-EXPAND4 scales to locations with three or four controlled devices without the complexity or cost of deploying a full control processor.