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Black Box TL421A 4-Port Modem Splitter compact network switch

Black Box Corporation

Black Box TL421A 4-Port Modem Splitter network switch

SKU CH-WXZJ-HC4DZ MPN TL421A

A compact four-port modem splitter lets four RS-232 terminals share one modem without extra lines

  • Weight0.32
  • Four terminals share one modem line
  • No user-configurable switches or jumpers needed
  • Master port uses RJ-45 straight-through cable
  • Only one terminal transmits at a time
  • Compact design saves installation space

4-Port Modem Splitter for Shared Access

The Black Box TL421A is a compact 4-Port Modem Splitter that lets four terminals share a single modem. It connects via RS-232 on RJ-45 interfaces to eliminate the expense of additional modems and lines. The unit requires no user-configurable switches, jumpers or settings for operation. Simply attach the modem and terminal devices, then power up as normal.

Verify RS-232 Terminal Compatibility

Confirm that your existing modem and terminal (DTE) devices support RS-232 signalling over RJ-45 connectors before ordering. The master port links to the modem using an RJ-45 straight-through cable with the appropriate RJ or DB adapter. Ports 1 through 4 connect directly to your DTE terminals. Only one terminal can transmit data to the modem at any given time.

Suits Multi-Terminal Legacy Setups

This splitter suits environments where multiple legacy terminals need economical access to a single modem connection. It is not intended for simultaneous multi-user data transmission or modern Ethernet networking applications. Buyers needing concurrent throughput or IP-based switching should consider alternative network infrastructure.

Highlights

  • Four terminals share one modem line
  • No user-configurable switches or jumpers needed
  • Master port uses RJ-45 straight-through cable
  • Only one terminal transmits at a time
  • Compact design saves installation space

Specifications

BrandBlack Box Corporation
Weight0.32
Shipping weight0.06 kg
Package size168 × 108 × 64 mm

Questions about this item

What comes in the box with the TL421A and what must be bought separately?

The splitter unit itself is included; you need to supply an RJ-45 straight-through cable and the correct RJ or DB adapter for the modem connection.

Which version of the 4-Port Modem Splitter should I choose?

Only the TL421A model is offered, so there are no alternate versions or capacities to select.

What does the 4-port RS-232 on RJ-45 specification mean when the unit is installed?

It provides one master port for the modem and four terminal ports, allowing four DTE devices to share the modem one at a time.

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