4-Port AV Control Expander — Serial, Relay & Ethernet
KanexPro CR-EXPAND4 4-port AV control expander with RS-232/RS-485/RS-422, 4 relay outputs, and Ethernet for remote multi-device serial and relay control.
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
Specifications| Specification | Value |
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| MAIN COM | 1× RS-232 (7-pin Phoenix) — connects to processor or PC |
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| COM 1–2 (Extended) | 2× RS-232/RS-422/RS-485 + HW flow (9-pin Phoenix) |
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| COM 3–4 (Extended) | 2× RS-232 + HW flow (5-pin Phoenix) |
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| NEXT COM | 1× daisy-chain output (7-pin Phoenix) |
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| Baud Rate | 2400–115200 |
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| Relay | 4× normally open (1A 24VDC/AC), 8-pin Phoenix |
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| Ethernet | 10/100M RJ45, TCP/UDP |
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| Power | DC 24V/1A (no PoE) — <2W |
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| Dimensions | 5.79" × 5.12" × 1.65" (147 × 130 × 42 mm) |
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| Weight | 1.48 lbs (673g) |
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| Housing | Metal enclosure, black |
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| Operating Temp | 32°F – 104°F (0°C – 40°C) |
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| Storage Temp | -4°F – 140°F (-20°C – 60°C) |
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| Humidity | 20%–90% RH (non-condensing) |
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| 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/1 |
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Questions
- What serial protocols?
- COM 1-2: RS-232/485/422 + HW flow. COM 3-4: RS-232 + HW flow.
- Relay capacity?
- 4 contact closure outputs.
- Third-party compatible?
- Yes, TCP/IP and UDP over Ethernet.
- Works with HOST6S/HOST8R?
- Yes, designed as companion expander.
- PoE support?
- No, DC 24V only. Use CR-EXPAND1 for PoE.
- Mounting?
- Compact desktop/shelf. Equipment closets or behind equipment.
- No connection?
- Check Ethernet, PWR/LAN LEDs, IP/subnet.
- Factory reset?
- Press RESET on rear panel.
- Licensing?
- No recurring fees.
- Daisy-chain?
- Yes via NEXT COM port.