Freedom R8100 SERIES, Руководство оператора

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2.2.7.6
NXDN™ Test Mode (trunking)
2.2.7.6.1
NXDN™ transmitter tests
The optional R8100 NXDN™ Type C Trunk Test Mode allows testing of trunked NXDN™) compliant
radios. NXDN™ radios use a digital transmission format employing Continuous 4 level FM (C4FM)
modulation. The R8100 NXDN™ Type C Trunk mode simulates the functions of a NXDN™ central
controller with the control and voice channel protocols needed for various tests. Also included are NXDN
compliant test patterns for Bit Error Rate (BER) testing, Frequency Error and Power meters, an Eye
Diagram with graphical representation of the NXDN™ signal, and modulation signal quality meters.
A Voice Loop feature (U.S. patent 5703479) is engaged for audio verification of the radio’s end-to-end
operation after the subscriber unit transmits. During a Voice Call the R8100 automatically records voice
channel data while the subscriber unit PTT is pressed, then retransmits it to provide audio verification of
the radio’s end-to-end operation.
The manufacturer’s Radio Service Software (RSS) is required to perform some tests in NXDN™ Type C
Trunk mode because certain measurements (BER) require placing the radio in a special test mode. Figure
3.2.8.6.3-1 shows the R8100 main screen after choosing the NXDN™ Type C Trunk Test Mode.
As usual, the RF Zone can be used to configure various settings such as output level, attenuation, and
ports, etc. However, the soft keys for Monitor and Generate frequencies are disabled. These frequencies
are determined by settings in the NXDN™ Type C Trunk zone, either the control/voice channel frequency
settings or the control/voice channel number settings according to the Band Plan Table.
Note: RF Zone Monitor and Generate frequency settings can be changed for the BER Test. Otherwise,
they are read-only and updated in real-time to show the control channel frequencies or the voice channel
frequencies that are in use.