User's Manual

TC12 Installation, Commissioning & Maintenance Handbook
4.3.2.3 Connection to OTU PCB
There are two sockets on the front of the OTU PCB. The sockets are labelled on
the silk screen. The top socket is reply and the bottom socket is control.
4.3.3 Front Panel Switches
4.3.3.1 Mains Switch
Mains switch and PC switch
Switching the Test Set off, using the rocker switch on the front panel, does NOT
guarantee isolation from the mains.
4.3.3.2 Modem Mode Switch and Mode Set Switch
To select the transmission mode the following procedure should be followed;
Press and hold down the modem set button (before moving the modem mode
select switch).
Whilst keeping the mode set button depressed, turn the modem mode switch to
the appropriate setting.
Release the modem set button.
Note. If the modem set button is not depressed whilst the modem mode select
switch is being moved, the test set may enter an unknown mode.
BELL Modes:
Switch Setting (Baud) Full Description
1200 equ Bell 202 with Equaliser Loopback
1200 Bell 202 Main Loopback
300 Bell 103
CCITT Modes:
Switch Setting (Baud) Full Description
1200 equ CCITT V.23 M2 with Equaliser Loopback
1200 CCITT V.23 M2 Main Loopback
600 CCITT V.23 M1
300 CCITT V.21
Note Selections at 300 Baud are Originate when the test set is in Instation
mode and Answer when the test set is in Outstation mode, and a mixture
when in monitor mode (i.e. test set modem 1 control in Answer mode, test
set modem 2 reply in Originate mode). This requirement is an automatic
selection made by the test logic board. The user simply has to select 300
baud and ITS mode.
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