User`s guide

Use Your System 4
Agilent E6474A User’s Guide 89
LEDs and Display During Power-up
The upper front panel LED indicates Power, and and the lower
LED indicates 1PPS (Pulse Per Second). The information shown
on these two LEDs comes from the GPS receiver. One use of the
1PPS would be to indicate that the GPS receiver is active. 1PPS
is also available at pin 9 of the rear panel RS-232 DB9 connector
and is enabled by software..
The Agilent direct connect GPS/DR status LCD displays
power-up and navigation status messages. The front panel LEDs
indicate CPU status, speed pulse status, and serial port activity.
Determining GPS Receiver Status
You can determine whether the GPS Receiver is ready to
navigate by using the E6474A software as follows:
1 Start the E6474A software, and select Tools > Navigation to
display the Navigation dialog box.
2 Click the Live Mode button.
3 When the GPS Navigator is ready to track, the Satellites box
shows the number of satellites tracked, and the Navigation
display shows either 2D or 3D, with the GPS Status
displaying “Tracking.” Both speed and direction are also
displayed. If the Nav Mode shows 3D, the altitude readings in
the display are also valid.
Before starting a data collection test, allow three minutes for
the unit to acquire GPS position data. During a data collection
test, navigation data is also combined and collected.
Calibration of Dead Reckoning
The Dead Reckoning calibration system is virtually
self-calibrating and requires minimal user intervention. Once
the Agilent direct connect GPS/DR is properly connected and
the unit is powered on for the first time, it is not yet calibrated
and operates as a normal GPS receiver.