PXIe-3352 User Manual
Publication No. 981049 Rev. B
Software Operation 4-2
Astronics Test Systems
If the Rubidium has warmed up, the front panel may look like as follows. It may
take up to 32 seconds to get the GPS to lock from the cold start.
GPS module is selected by dragging the Discipline Mode switch to its “ENABLE”
position. Once the GPS module is locked onto a sufficient number of GPS
satellites, the front panel will display the Latitude and Longitude information. At the
same time, the “1PPS Input Detected” soft LED will be illuminated.
If the 1PPS Input switch is set to “GPS”, then the Rubidium module is disciplined
by the GPS. Otherwise, an external 1 PPS source is required to discipline the
Rubidium oscillator.
If Discipline Mode is disabled, the Rubidium oscillator will be running on its own
calibrated clock source. The clock that is output from the 1PPS OUT port is always
sourced by the Rubidium oscillator.