Multitech MT202TD, Руководство пользователя

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Chapter 2 - Installation & Connection
17
Leased Line Connections
The MT202TD modem operates on leased lines and may
be configured in two ways: two-wire or four-wire. In a
leased-line application, the line is continuously connected
to the modem. In two-wire leased-line applications, only
one modem may transmit at a time (this is known as half-
duplex). In a four-wire configuration, one pair of wires
should connect to the transmitter of the local modem and
the receiver of the remote modem. The other pair of wires
should connect to the remote modem’s transmitter.
Digital Analog
Local Modem Computer or Terminal Remote Modem
Analog Digital
Computer or Terminal
UUUUU
UUUUU
Figure 3-1. Four-Wire Leased Line Connection
In multi-point leased line configurations, the user must
arrange to have the phone company install the multi-point
network using a four-wire configuration. The following
illustration shows a typical bridged multi-point configura-
tion.
MT202T MT202T MT202T
MT202T MT202T
MT202T MT202T
B B B
600 ohms 600 ohms
Boxes marked
“B” are Bridge
Circuits
Figure 3-2. Four-Wire Multi-Point Connection