Symmetricom XL-GPS GPS Receiver User Manual


 
997-01530-01, Rev. C-25, Jan 2008 57
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SSSSSSSSSSSS SSSS SSSSSS SSSSSSS S SSS SSSSSSS
Current: the XL-GPS is using the satellite’s GPS signal to calculate time and position.
Bad: the GPS satellite is transmitting information that it has been removed from service.
Rejected: the XL-GPS M12 receiver’s TRAIM feature has detected anomalous signals from this
satellite and has quarantined it from the timing solution for 12 hours.
GPS satellite signal strengths are reported in units of dBW. Signals below -170 dBW (e.g., -171 dBW)
are not usable by the GPS receiver. See “
GPS Signal Strength Requirements” on page 15.
If you’re using the keypad interface, use the UP/DOWN ARROWs to scroll through the list of satellites.
Command Line
Use Serial Function F60 to request a list of all, current, and tracked satellites. To display the list, enter a
string using the following format:
F60<S><TYPE><CR>
XL-GPS responds with approximately 32 lines that use the following format:
F60<S>prn<NN><S><STATE> tracked current<LEVEL><CR><LF>
where:
For example, to display the complete GPS satellite list, enter:
F60 ALL<CR>
F60 responds:
F60 = ASCII string indicating function F60.
<S> = ASCII space character one or more.
B = ASCII letter to denote Option Bay number follows
<N> = Option Bay Number, 1 through 10.
<SEP> = One or more separator characters; either space, comma or tab.
<TYPE> = ALL, CURRENT, TRACKED, BAD, or REJECTED.
<CR> = Carriage return character.
prn = Pseudo Random Number
<NN> = 1 through 32 (prn<NN> identifies specific GPS satellites)
<STATE> = Good, Bad, or Unknown
tracked = Either “tracked” or blank
current = Either “current” or blank
<LEVEL> = Satellite signal strength in dBW
<LF> = Line feed character