4-Port AV Control Expander — Serial, Relay & Ethernet
Extend multi-device serial and relay control to remote locations over your existing network
Resellers, installers, schools and businesses. Approval is usually the same working day.
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.
- MAIN COM (RS-232) + 4 extended serial ports — 5 serial connections total
- COM 1–2: RS-232/RS-485/RS-422 with hardware flow control
- COM 3–4: RS-232 with hardware flow control
- NEXT COM daisy-chain output for cascading multiple expanders
- 4× relay outputs, normally open (1A 24VDC/AC)
- 10/100M Ethernet with TCP/UDP — TCP ports 8001–8004 per serial
- Built-in web server for browser-based configuration
- DC 24V/1A power (24V adapter included) — no PoE
- Front panel LEDs: PWR, LAN, 4× relay, MAIN TX/RX, COM 1–4 TX/RX
- Metal enclosure: 147mm × 130mm × 42mm, 673g
| Specification | Value |
|---|---|
| MAIN COM | 1× RS-232 (7-pin Phoenix) — connects to processor or PC |
| COM 1–2 (Extended) | 2× RS-232/RS-422/RS-485 + HW flow (9-pin Phoenix) |
| COM 3–4 (Extended) | 2× RS-232 + HW flow (5-pin Phoenix) |
| NEXT COM | 1× daisy-chain output (7-pin Phoenix) |
| Baud Rate | 2400–115200 |
| Relay | 4× normally open (1A 24VDC/AC), 8-pin Phoenix |
| Ethernet | 10/100M RJ45, TCP/UDP |
| Power | DC 24V/1A (no PoE) — <2W |
| Dimensions | 5.79" × 5.12" × 1.65" (147 × 130 × 42 mm) |
| Weight | 1.48 lbs (673g) |
| Housing | Metal enclosure, black |
| Operating Temp | 32°F – 104°F (0°C – 40°C) |
| Storage Temp | -4°F – 140°F (-20°C – 60°C) |
| Humidity | 20%–90% RH (non-condensing) |
| Package Contents | 1× Expander, 2× 5-pin Phoenix, 2× 7-pin Phoenix, 1× 8-pin Phoenix, 2× 9-pin Phoenix, 4× Screw, 2× Mounting Ear, 1× 24V/1A Adapter, 1× Manual |
Buying for resale or a project?
Trade accounts see net pricing, stock by warehouse and one-click reorder from past jobs. Approval is usually the same working day.