Pliant CREWCOM CB2, Руководство по эксплуатации

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Nulling
In order to minimize echo resulting from connection to an external 2-Wire system, it is necessary to
optimize the hardware of the hybrid circuitry in the BaseStation to match line impedance. The CB2
BaseStation provides a user-initiated Auto Null feature that automatically optimizes the 2-Wire interface.
Nulling only impacts 2-Wire hard wired intercom connections. Auto Null sends a series of tones to each
of the 2-Wire intercom channel connections. Activate Auto Null for new connections or whenever the 2-
Wire system changes, such as when additional non-CrewCom wired Packs are added or removed, or
when cable lengths are changed.
During the nulling process, the BaseStation DSP monitors the echo and adjusts the line characteristics
(Resistance, Inductance, and Capacitance) to optimize the interface to the external 2-Wire system.
When Auto Null is initiated, all of the functions, including communication, of the intercom channel being
nulled are interrupted. The nulling process takes approximately 10–15 seconds per channel. You may
need to re-adjust the intercom levels to a proper level after the 2-Wire intercom lines have been nulled.
Optimize 2-Wire port hardware connections by nulling them in order to minimize echo in the physical link
and to enable the software to remove any residual echo. You may null from the BaseStation’s menu.
Aut o Null from t he BaseSt at ion
During the Auto Null process, the BaseStation LCD will display each 2-Wire port’s resistance (R),
inductance (L), capacitance (C) and amplitude.
There are two options for auto nulling your CrewCom system – Null All and Null by Port . The following
steps detail how to initiate the Auto Null process from the BaseStation:
1. Turn off all Talk buttons on wired equipment. Since the BaseStation monitors a self-generated
tone to adjust the null characteristics, any sounds entering through the wired intercom system will
interfere with the nulling process.
2. On the BaseStation, press Menu to open the main menu.
3. Scroll through the menu options to the Wired Settings and select Auto Null .
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