ComNav Vector G2, Руководство по установке и эксплуатации

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ComNav G2 & G2B Installation & Operation Appendices
Document PN 29010093 V1.5 - 68 -
16 December 2016
Appendix 4
Configure Beacon stations for G2B
G2B compass has an internal beacon receiver. The internal beacon receives pseudo range
corrections from Radiobeacon stations with a carrier frequency from 283.5 kHz to 325 kHz.
The beacon receiver can scan beacon signals from that range automatically, or it can search
for specific frequencies depending on the configuration. Out of factory the beacon receiver is
configured to automatically search for a beacon reference station within the frequency range
at a step of 500 Hz once the G2B is powered on. This default configuration allows G2B to
work at different locations worldwide.
At some locations, automatic scan for a beacon station may take a long time (up to 35
minutes). If you know the information of a beacon station or stations close to the G2B, you
can significantly reduce the lengthen search time by limiting the frequencies to be scanned.
The next section describes how to do so.
The information you must know about the beacon station is its frequency.
You communicate to G2B’s internal beacon model the same way you configure the G2B
through its RS232 Port1. Connecting the port a PC COM port, and through a general
hyperterminal style program, you can check the beacon receiver status and change its
configuration easily.
Enter and exit the beacon configuration mode
Before you can change the beacon configuration, you must enter the beacon configuration
mode. This command will place G2B into the beacon configuration mode:
$PCMNBC,COMMAND<CR><LF>
After entering the configuration, you can exit it by issuing:
$PCMNBC,DATA<CR><LF>
Send a configuration command to the beacon
In the beacon configuration mode, you can send a command to the beacon through the
following sentence:
$PCMNBC,SEND,command[ parameter name][ parameter list]<CR><LF>
The commands the G2B internal beacon supports are summarized in Table 22.
Change the beacon scanning mode
The beacon has 2 scanning modes, AUTOMATIC scan and MAPPED scan. In AUTOMATIC
scan mode, the beacon scans the full frequency range from 328.5 kHz to 325 kHz at 500 Hz
steps. In MAPPED scan mode, the beacon looks for the frequencies from a frequency table
and scans each frequency circularly.
Create and/or modify Channel Map Table
The frequency table is called Channel Map Table; each item in the table has 2 columns. One
is named Channel, and the other Frequency. You can check the content of the table in your
unit by issuing:
$PCMNBC,SEND,MAP<CR><LF>
Figure 20 shows an example of Channel Map Table output. The table has 4 frequencies that
occupy from channel 1 to channel 4.