ZED-F9K - Integration manual
Time pulse settings shall be chosen in such a way that neither the high nor the low period of
the output is less than 50 ns (except when disabling it completely), otherwise pulses can be
lost.
3.9.10.5.1 Example
The example below shows the 1PPS TIMEPULSE signal generated on the time pulse output
according to the specific parameters of the CFG-TP-* configuration group:
•
CFG-TP-TP1_ENA
= 1
•
CFG-TP-PERIOD_TP1
= 1 000 000 µs
•
CFG-TP-LEN_TP1
= 100 000 µs
•
CFG-TP-TIMEGRID_TP1
= 1 (GPS)
•
CFG-TP-PULSE_LENGTH_DEF
= 0 (Period)
•
CFG-TP-ALIGN_TO_TOW_TP1
= 1
•
CFG-TP-USE_LOCKED_TP1
= 1
•
CFG-TP-POL_TP1
= 1
•
CFG-TP-PERIOD_LOCK_TP1
= 100 000 µs
•
CFG-TP-LEN_LOCK_TP1
= 100 000 µs
The 1 Hz output is maintained whether or not the receiver is locked to GPS time. The alignment to
TOW can only be maintained when GPS time is locked.
Figure 22: Time pulse signal with the example parameters
3.9.11 Timemark
The receiver can be used to provide an accurate measurement of the time at which a pulse was
detected on the external interrupt pin. The reference time can be chosen by setting the time source
parameter to UTC, GPS, GLONASS, BeiDou, Galileo or local time in the CFG-TP-* configuration group.
The UTC standard can be set in the CFG-NAVSPG-* configuration group. The delay figures defined
with CFG-TP-* are also applied to the results output in the UBX-TIM-TM2 message.
A UBX-TIM-TM2 message is output at the next epoch if
• The UBX-TIM-TM2 message is enabled, and
• A rising or falling edge was triggered since last epoch on one of the EXTINT channels.
The UBX-TIM-TM2 messages includes the time of the last timemark, new rising/falling edge
indicator, time source, validity, number of marks and an accuracy estimate.
Only the last rising and falling edge detected between two epochs is reported since the
output rate of the UBX-TIM-TM2 message corresponds to the measurement rate configured
with CFG-RATE-MEAS (see
UBX-20046189 - R01
3 Receiver functionality
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Early production information
