1Pps Output; Gnss Fix Output - Advanced Navigation Spatial Reference Manual

Function
Wheel Speed Sensor
Wheel Encoder Phase A
Wheel Encoder Phase B
Event 1 Input
Event 2 Input
TSS1 Output
Simrad 1000 Output
Simrad 3000 Output
Serial Port Passthrough
GNSS Receiver Passthrough
Gimbal Encoder Phase A
Gimbal Encoder Phase B
Odometer Direction, Forward Low
Odometer Direction, Forward High
Reverse Alignment, Forward Low
Reverse Alignment, Forward High
Zero Angular Velocity Input
Table 19: GPIO pin and auxiliary RS232 functions
12.4.1

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 Spatial has accurate time or not. It is important to note
that when Spatial acquires time corrections from its 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 20: 1PPS Specifications
12.4.2

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.
Spatial Reference Manual
Type
Frequency Input
Frequency Input
Frequency Input
Digital Input
Digital Input
Serial Transmit
Serial Transmit
Serial Transmit
Serial
Serial
Frequency Input
Frequency Input
Digital Input
Digital Input
Digital Input
Digital Input
Digital Input
Voltage Level
-5v to 5v
0 to 5v
Page 94 of 158
Version 4.4
04/06/2019
GPIOs
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1
1
1
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Trigger
Falling Edge
Rising Edge
Auxiliary
RS232
Receive
Receive
Receive
Transmit
Transmit
Transmit
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Receive
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