1Pps Output; Gnss Fix Output; Odometer Input; Zero Velocity Input - Advanced Navigation Motus Reference Manual

15.4.1

1PPS Output

In this function, the pin pulses for 50 milliseconds to signal the precise second. The
1PPS line starts pulsing approximately 100 milliseconds after power up and always
fires irrespective of whether Motus has accurate time or not. It is important to note
that when Motus acquires time corrections from a GNSS receiver, the 1PPS signal may
fire at an interval of less than 1 second. This typically only occurs the first time the
GNSS receiver obtains a fix after startup. The time initialised status flag can be used to
determine whether the time and 1PPS line is accurate or not.
1PPS Source
Auxiliary
GPIO
Table 24: 1PPS Specifications
15.4.2

GNSS Fix Output

In this function, the pin is low when there is no GNSS fix or a 2D fix and high when
there is a 3D, SBAS, Differential or RTK GNSS fix.
15.4.3

Odometer Input

This function is designed for low resolution vehicle speed sensors and odometers. It
expects a normally low input with a high state for the trigger. If the pulse length is
more than 0.1 metres this odometer input function should be used, if it is less than 0.1
metres the wheel speed sensor function should be used. Please contact Advanced
Navigation support for help integrating with your speed sensor.
Parameter
Trigger
Maximum Frequency
Maximum Pulse Rate
Table 25: Odometer Specifications
15.4.4

Zero Velocity Input

When using this function, a high state indicates to Motus that it is stationary. The low
state indicates that the vehicle is not stationary. Use of this function can significantly
improve drift performance when a GNSS signal is not available.
15.4.5

Pitot Tube Input

This function is designed for fixed wing aircraft to enhance navigation through the use
of a pitot tube to measure airspeed. It requires a differential pressure sensor that has a
frequency output such as the Kavlico P992 (frequency output option) or the
Paroscientific series 5300. Please contact Advanced Navigation support for help
integrating with a pitot tube.
Motus Reference Manual
Voltage Level
-5 V to 5 V
0 to 5 V
Page 94 of 146
Version 1.1
29/11/2019
Trigger
Falling Edge
Rising Edge
Value
Low → High
600Khz
4294967 pulses/metre