SX BLUE GPS iSXblue II+ GNSSTM, User Manual

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SXblue Series User Manual 65
Note - For successful communications, the baud rate of the SXblue receiver
serial ports must be set to match that of the devices to which they are
connected. Technical Reference Manual describes the $JBAUD baud rate
change command.
2.10.3 Event Marker, 1 Pulse per Second and 5Vdc Power
The 1PPS, EM and 5Vdc Power are available upon request on the DB-9 connector
when ordering the SXblue receiver. These features can also be activated after
purchase but you will need to contact your local reseller.
2.10.3.1 One Pulse per Second (1PPS)
The one pulse per second (1 PPS) timing signal is used in applications where
devices require time synchronization.
The 1 PPS signal is 3.3V HCMOS normally low with rising edge synchronization.
The 1 PPS signal is capable of driving a load impedance which is greater than 10
kΩ in parallel with 10 pF capacitor. The pulse is approximately 1ms long.
2.10.3.2 Event Marker Input (EM)
Depending on your application, you may have the need to force a GPS solution at
a particular instance, not synchronized with GPS time. Such an application could
be to compute the location of a perspective center of a camera being used for a
photogrammetric application, where the aircraft moves with considerable speed
and an interpolation between two GPS epochs could be unreliable.
The Event Marker input is active low 3.3V HCMOS with falling edge
synchronization. The input impedance and capacitance is higher than 10
kΩ
and
10 pF respectively, with a threshold of lower than 0.7V required to recognize the
input.
Upon detecting and Event, the SXblue receiver will output immediately the set of
strings it has been configured to output. Also it is worth noting that binary message
(Bin1) has a field reserved for the event marker. See Technical Reference Manual
for more information.
2.10.3.3 5 volts DC Output (PWR)
Some external sensor might require a 5Vdc power source. An example can be
attaching an RS-232 Bluetooth or Wi-Fi dongle to the receiver. The SXblue