Ethernet to 4-Port RS-232 Serial Server

Part: 4401   Model: SeaLINK+4.232

(1 customer review)


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The 4401 Ethernet to serial server is the easiest way to connect serial ports to your Ethernet network. Each RS-232 port implements all modem control signals for maximum compatibility with a wide range of peripherals. SeaLINK® products use industry-standard RFC 2217 TCP/IP protocol for maximizing compatibility with the widest range of applications and devices.

Sealevel’s SeaLINK software drivers and utilities make installation and operation easy using Microsoft Windows operating systems. After software installation, the 4401’s serial ports appear as virtual COM ports to the host machine. Standard serial operating calls are transparently redirected to the 4401, guaranteeing compatibility with legacy serial devices and enabling backward compatibility with existing software. Serial tunneling is also supported, allowing two native serial devices to communicate over a network. Alternatively, raw data socket mode is supported, eliminating the need for a driver.

The 4401 is compatible for use with Linux; please contact Sealevel Tech Support for suggested open-source software resources.

To simplify installation and configuration, a printed copy of the SeaLINK QuickStart Guide is included with all Ethernet serial server orders.


Additional information




8.6 (L) x 6.1 (W) x 2.0 (H)

Electrical Interface


Humidity Range

10 – 90% Relative Humidity, Non-Condensing

Host Interface(s)


Max Data Distance

50 feet

Max Data Rate

230.4K bps

Operating Temperature

0°C to 70°C (32°F to 158°F)

# of Ports


Power Requirement

+5V @ 1A

Serial Connector(s)


Storage Temperature

-50°C to 105°C (-58°F to 221°F)

  • Ethernet 10/100BaseT (autosense)
  • Appears as a virtual COM port to host machine
  • Data rates to 230.4K bps
  • Supports custom baud rates and 9-bit protocol
  • Four DB9M connectors with full modem control signals implemented
  • Hot-swappable
  • Built-in watchdog/reset circuit automatically recovers the converter from unexpected error-states
  • DIN rail mounting option (Item # DR103)
  • Includes 120V AC adapter that outputs 5VDC @ 2.4A (Item# TR101)
  • Includes 7′ Ethernet patch cable (Item# CA246) and 7′ Ethernet crossover cable (Item# CA251)
  • Sealevel SeaLINK software supports Microsoft Windows and Linux operating systems


Datasheet: 4401

1 review for SeaLINK+4.232

  1. TJ

    Trouble free up and download
    As we added more and more CNC machines to our shop, we had to start using mechanical switch boxes to have enough ‘connections’ to various computers we used for up and downloading. Then we moved into additional areas of the shop with even more machines and the problems just got worse. 9 machines in one place, 3 in another, 6 in another. What a pain. And then my right hand man discovered SeaLevel and that Ethernet to Serial gadget you guys make. We bought one and hooked it up to our LAN and it worked like it had been there forever. That was in the area with 9 machines, so we still had 2 machines on a switch (ugh) but will soon pickup a 4 port and make it right. We right away bought another 8 port for the area with 6 lathes. Yawn, no problem. And just recently added another 4 port unit to cover the newest machines. It’s hard to get excited with these SeaLevel things because they just flat work like we want ’em to. End of story.

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