ComNav Vector G2, Installation & Operation Manual

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ComNav G2 & G2B Installation & Operation
Document PN 29010093 V1.5 - 43 -
16 December 2016
Operation
The G2 Satellite Compass provides accurate, reliable, high-precision position and heading
data. It is intended to be used with a wide variety of marine Navigation equipment.
The G2 is a very good example of a classic “Black Box”:
•
There are no switches or indicators on the case … not even a power light …
•
It begins to operate as soon as it is powered on …
•
But … there is NO way to tell if it is working!!
As mentioned in the Overview chapter, the factory-default configuration settings are meant to
allow most users, in typical marine applications, to install and use the G2, with no changes
needed …
Plug and Play , in other words!
So, in that sense, there’s really no need for an “Operating the G2” chapter in this manual.
On the other hand, since the G2 really is a “Black Box” (despite the case being white …),
there is
no way to tell if it is working properly, or to control it, if it is not connected to at least
one suitable external device … such as a GPS Compass Display, or a PC running a suitable
program.
And so, the information in this chapter is meant to show how to monitor the operation &
status of the G2, and to control it and/or re-configure it, when necessary.
The first part of this chapter will help you gain some understanding of how the G2 works.
The second part describes monitoring & controlling & configuring the G2, and other
performance & setup information.
Understanding How the G2 Works
The first thing to do, in order to “operate” a G2, is to turn it on …
Power should always be applied to the G2 by means of a power switch (in series with a
suitable fuse or circuit breaker, see page 29).
Automatic & Continuous Operation
When first powered up, the G2 performs a “cold start” – which involves determining which
satellites are in view, and then acquiring signals from all that are in view.
The DGPS data source is also automatically acquired, if the G2 has been set to use DGPS
data.
Once sufficient satellite signals are acquired, the G2 begins to generate navigational data,
which is then sent out on the G2’s two serial ports, according to what it has been configured
to output.
While the G2 remains powered, its satellite receivers & processors are always operating.
GPS and GLONASS
United States’ Global Positioning System, commonly referred as GPS, is the first global
navigation satellite system in operation. It used to be the only navigation satellite system with
global coverage and high precision. However by 2010 alternative system with global
coverage and comparable precision became widely available for civilian use, which is the
Russian GLONASS. Both GPS and GLONASS are Global Navigation Satellite Systems.
The G2 employs GNSSS receivers that can work with both GPS and GLONASS systems
Acquisition Time
Although initial satellite signal lock may be reached in as little as 30 seconds, it may also take
as several minutes, depending on the current positions of the visible navigation satellites and
their relative signal strength. During this acquisition time, the position, heading, and other
data output may be transmitted on an intermittent basis, causing an “Invalid heading” or
similar alarms on navigation devices (such as autopilots and radar displays).