Configuration; Setup - ABB 23WT25 Manual

2

Configuration

2.1

Setup

Chapter 2 describes the connection of an NSK5 to a 23WT25 modem. It furthermore lists the
compatible transmission modes.
Both modems can be used in 2-wire as well as 4-wire connection. See Figure 1 for the wiring
scheme. in a point-to-point setup. The NSK5 modem has an optional additional backup line
(denoted by identifier "2") in case the main connection is broken. This switchover circuit is
not available on a 23WT25.
A modem at the end of a transmission line has to be terminated correctly. Please see 2.3 for
details for the 23WT25 modem and 2.5 for the NSK5 modem. If a modem is staggered some-
where in the run of a transmission line, it has to be configured to be high-impedant.
Integrated data regeneration is not featured. on the 23WT25. There is also no local test loop
according to ITU-T V.54 available for the 23WT25 modem.
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Figure 1: Communication setup for 23WT25 and NSK5
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