User's Manual

Page 2
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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.