Purpose Of Pps; Electrical Interface And Transmission Settings; Table 12. Electrical And Transmission Specifications - quanergy M8 User Manual

Purpose of PPS

The PPS signal (nanosecond counter) provided by the GPS receiver is required to make the
NMEA timestamp highly accurate with guaranteed reliability. The GPS unit's PPS signal
frequently corrects local PPS from drifting to provide a highly accurate clock.
• Seconds count up in Unix time (seconds elapsed since 1 January 1970).
• Nanoseconds count up 0 to 999999999, when it overflows and restarts from 0.
(If the sensor continues running when input from the GPS receiver is interrupted, the
sensor's internal clock will continue incrementing the timestamp in whole seconds.)

Electrical Interface and Transmission Settings

By default, the M8 sensor is set to receive GPS communication at the industry standard
4800 baud rate. Some units may allow higher baud rates to enable the transmission of
more data, but other units may require a lower baud rate.
Transmission requirements and preferences may require changing the baud rate to match,
as discussed in the "Managing the Sensor" section, especially page 49.
Relevant specifications are listed in Table 12.

Table 12. Electrical and Transmission Specifications

Item
Electrical Interface
Voltage Level
Baud Rate
Data Bits
Parity
Stop Bits
Pulse Width
NMEA
TIA-232-F compatible
–6 V to +6 V
4800 bits per second (changeable)
8
None
1 (or more)
NA
M8 Sensor User Guide, QPN 96-00001 Rev K
PPS
LVTTL
+5 V maximum
NA
NA
NA
NA
10 milliseconds minimum
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