RCB-F9T - Integration manual
3.8.1.4 Time pulse configuration
u-blox RCB-F9T receivers provide a time pulse (TIMEPULSE) signal with a configurable pulse period,
pulse length and polarity (rising or falling edge).
It is possible to define different signal behavior (i.e. output frequency and pulse length) depending
on whether or not the receiver is locked to a reliable time source. Time pulse signal can be configured
using the configuration group CFG-TP-*.
3.8.1.5 Configuring time pulse with CFG-TP-*
The configuration group CFG-TP-* can be used to change the time pulse settings, and includes the
following parameters defining the pulse:
•
timepulse enable
- Time pulse is active if this item is set.
•
frequency/period type
- Determines whether the time pulse is interpreted as frequency or
period.
•
length/ratio type
- Determines whether the time pulse length is interpreted as length[us] or
pulse ratio[%].
•
antenna cable delay
- Signal delay due to the cable between antenna and receiver.
•
pulse frequency/period
- Frequency or period time of the pulse when locked mode is not
configured or active.
•
pulse frequency/period lock
- Frequency or period time of the pulse, as soon as receiver has
calculated a valid time from a received signal. Only used if the corresponding item is set to use
another setting in locked mode.
•
pulse length/ratio
- Length or duty cycle of the generated pulse, either specifies a time or ratio
for the pulse to be on/off.
•
pulse length/ratio lock
- Length or duty cycle of the generated pulse, as soon as receiver has
calculated a valid time from a received signal. Only used if the corresponding item is set to use
another setting in locked mode.
•
user delay
- The cable delay from the receiver to the user device plus signal delay of any user
application.
•
lock to GNSS freq
- Use frequency gained from GNSS signal information rather than local
oscillator's frequency if item is set.
•
locked other setting
- If this item is set, as soon as the receiver can calculate a valid time, the
alternative setting is used. This mode can be used for example to disable time pulse if time is
not locked, or indicate lock with different duty cycles.
•
align to TOW
- If this item is set, pulses are aligned to the top of a second.
•
polarity
- If set, the first edge of the pulse is a rising edge (pulse polarity: rising).
•
grid UTC/GNSS
- Selection between UTC (0), GPS (1), GLONASS (2) and BeiDou (3) timegrid.
Also affects the time output by UBX-TIM-TP message.
The maximum pulse length cannot exceed the pulse period.
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.
RCB-F9T time pulse 1 default configuration: UTC time, frequency is 1 Hz and pulse length is
100 ms when GNSS is not locked and 200 ms when GNSS is locked.
3.8.1.5.1 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
= 100 000 µs
UBX-19003747 - R04
3 Receiver functionality
Page 32 of 54
Early production information
