1 How To...
1.27
Generate a "Pulse Per Second" Signal
The receiver is able to generate an x-pulse-per-second (xPPS) signal aligned with a selected
GNSS system time, with UTC or with the internal receiver time.
The
command is used to set the xPPS parameters (rate, polarity, time
system, ...). For instance, to synchronize the xPPS pulses with UTC and have one pulse every
ten seconds, use:
setPPSParameters,sec10, , ,UTC <CR>
D
True PPS
position
PPS as generated
by receiver
Receiver digital clock
D=
xPPSOffset
Figure 1-3:
xPPS output granularity.
Although the position of the PPS pulse is computed accurately by the receiver, the actual
pulse is generated at the nearest "tick" of the internal receiver digital clock, as illustrated in
the figure above. This leaves an offset (noted "D" in the figure) between the true xPPS pulse
and the one actually generated by the receiver. This offset can reach a few nanoseconds. It
is available in real-time in the
SBF block.
To be able to align its xPPS output with the GNSS system time, the receiver needs a fresh
estimate of the GNSS time from its PVT solution. If the last PVT solution is older than a pre-
scribed timeout (set by the
command), no PPS pulse is generated. In
addition, to align its PPS with UTC, the receiver needs to have received the UTC offset param-
eters from the satellite navigation messages. If these parameters are not available and the
user has requested to align the xPPS with UTC, no xPPS pulse is generated.
49
Содержание PolaRx5TR
Страница 1: ...PolaRx5TR Reference Guide Applicable to version 5 5 0 of the Firmware ...
Страница 73: ...3 Command Line Reference Chapter 3 Command Line Reference 73 ...
Страница 108: ...3 Command Line Reference COM1 gca Ch05 CR R gca Ch05 ChannelAllocation Ch05 G01 auto 0 16000 COM1 108 ...
Страница 130: ...3 Command Line Reference COM1 gim CR R gim IonosphereModel off COM1 130 ...
Страница 147: ...3 Command Line Reference PVTMode Static StandAlone SBAS DGPS RTKFloat RTKFixed Cartesian1 COM1 147 ...
Страница 218: ...3 Command Line Reference COM1 esoc COM1 MeasEpoch CR R esoc COM1 MeasEpoch SBFOnce COM1 MeasEpoch COM1 218 ...
Страница 237: ...3 Command Line Reference COM1 237 ...
Страница 251: ...3 Command Line Reference Event type Command etime 1588343730 before 1440 after 1440 Planned Disk DiskEvent COM1 251 ...
Страница 279: ...3 Command Line Reference COM1 279 ...
Страница 294: ...4 SBF Reference Chapter 4 SBF Reference 294 ...