Users manual
Appendix A
Revision #:
A
Date:
07-14-15
Page
45
of
58
$PERDCRX,TPS2,1,2,0,200,+001000,0,0,0005,+0.000,1000*29
PPS status: PPS ON (1)
PPS mode: during on fix (2)
PPS period: 1PPS (0)
PPS pulse width: 200ms
PPS cable delay: +1000ns
Polarity: rising edge
Type: LEGACY PPS
Estimated accuracy: 5ns
Sawtooth: +0.000ns
PPS estimated accuracy threshold: 1us
Notes:
-
This command is output every second.
-
$PERDAPI,CROUT,X,0*40 stops outputting this command.
-
Output Values of period, pulse width, polarity are switched by pps type (LEGACY or GCLK).
-
PPS estimated accuracy means estimated difference between PPS of GT-87 and GPS, UTC (USNO)
or UTC (SU) timing which user sets by TIMEALIGN command. This is not guarantee value, but user
can use this value to get a rough idea.
-
Sawtooth means correction value under the resolution of GT-87, that is, about 3.5 ns.
-
Sawtooth value is applied to prior to the one second PPS.
Corrected PPS [t-1] = output PPS [t-1] + Sawtooth value [t]
