Differential Gps Traffic Light Operation; Red Flashing S; Red/Yellow Solid; Red Solid S - Leica MX420 Operator's Manual

Operator's Manual
Differential GPS Traffic Light Operation:
Red Flashing
Keypad & Display Description
Not tracking satellites (no position update). This is normal for the
first 2 minutes or so when turning the unit on. The very first time you
turn the unit on, or if the memory is reset or lost, this condition is also
normal, Allow the receiver to run for at least 30 minutes under these
circumstances. If it still does not change to Red Solid, refer to the
troubleshooting section of the Installation & Service Manual. An
icon similar to the one at left will be displayed in the upper left corner
of screen.
Red/Yellow Solid
Red Solid
Dead Reckoning. When normal GPS or OGPS operation is not avail-
able, this LED sequence is provided to quickly identify the OR naviga-
tion mode. A DR indicator is also displayed on all screens.
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Tracking one or more satellites (no position update). This is also
normal for the first 2 minutes or so when turning the unit on. The very
first time you turn the unit on, allow the receiver to run for at least 20
minutes after changing to Red Solid to collect an almanac from the
satellites, regardless of whether a position update has been calculated
or not. This is also a normal indication if the HOOP is greater than 10,
if the receiver is tracking too few satellites, or for other reasons as well.
Read the GPS and DGPS function screens for more information.
•
Yellow/Green Solid
GPSposition update; DGPS corrections are not being received. You
may see this from time to time during normal operation. It usually
occurs when the beacon signal is not available (either it is being blocked
by terrain or a local object or you are out of range of the transmitter)
and/or you are tracking 3, 4, or 5 satellites, and the satellites have poor
geometry relative to your position. The condition will normally go
back to green solid, when it picks up another beacon station. The
e
factory default level for dropping OGPS corrections is 60 seconds.
During this period, your positioning information is less than optimal,
and position accuracy may be off by as much as 3 to 5 meters. Press
the GPS function key and refer to the DGPS section in this manual for
guidance if this light condition occurs.
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