Black Box TL421A User manual

BL A C K B O X®
Split data from a single modem to four RS-232
DTEs.
Passive, non-powered. Operates transparent to data formats and speeds.
4-Port RJ-45 Modem Splitter (RS-232 on RJ-45)
Order toll-free in the U.S.: Call 877-877-BBOX (outside U.S. call 724-746-5500)
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TL421A

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4-Port RJ-45 Modem Splitter (RS-232 on RJ-45)
1. Specifications
Leads Supported — Pins 3, 4, 5, 7, and 8 connected straight through between the
Master and Ports1–4;
Pins 1, 2, and 6 “diode OR’ed” from Ports 1–4 to the Master port
Connectors — (1) single style RJ-45 socket connector (Master);
(1) quad-style RJ-45 connector (Ports 1–4)
Power — Non-powered; no power supply required
Size — 1"H x 2.3"W x 4.3"D (2.5 x 5.7 x 10.8 cm)
Weight — 0.25 lb. (0.11 kg)
2. Introduction
The 4-Port RJ-45 Modem Splitter (TL421A) is designed to allow multiple terminals to
share a single modem. This passive device is non-powered and transparent to data
formats, rates, and protocols. Data received from the modem is transmitted to all
attached terminal devices. Only one terminal device may send data to the modem at
a time. If more than one terminal device sends data at the same time, the data will
be corrupted. Connect the Master port to a DCE device, such as a modem, using an
RJ-45 straight-through cable and the appropriate RJ/DB adapter. All other ports,
labeled Port 1 through Port 4, connect to DTE terminal devices. When connected to
DTE devices, you don’t need crossover cables.

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724-746-5500 | blackbox.com
4-Port RJ-45 Modem Splitter (RS-232 on RJ-45)
3. Installation
There are no user-configurable settings in the 4-Port RJ-45 Modem Splitter. Simply
connect your modem or other DCE device to the Master port, and connect your
terminals or other DTE devices to Ports 1–4 on the Modem Splitter. For the GND
signal and any signals that flow from the DCE to DTE direction, use Pins 3, 4, 5, 7,
and 8. For signals that flow from the DTE to DCE direction, use Pins 1, 2, and 6. A
typical configuration would be to connect RTS, DTR, and TD to Pins 1, 2, and 6
respectively, and to connect RD, GND, RI, DCD, and CTS to Pins 3, 4, 5, 7, and 8.
Once all the connections have been made, power up your modem and terminals as
normal. The system is now ready for operation.

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TL421A, version 2
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