Hemisphere GPS Crescent Vector H220, Руководство интегратора

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H220 Integrator Guide Chapter 2 – Board Overview Page 16 of 28
The 1 PPS signal is 3.3 V CMOS active high with rising edge synchronization. The
1 PPS signal is capable of driving a load impedance greater than 10 kΩ in parallel with 10 pF.
The pulse is approximately 1 ms.
The H220 supports a programmable PPS. Users can select the frequency to 1,2,5 or 10Hz. The
H220 can support widths up to 900ms.
The width command parameter is in usec (microseconds).
$JPPS,RATE,<Rate_In_Hz (limited to 1.0 ,2.0 ,5.0 ,10.0 >,[SAVE]
or if you prefer to work with the period (inverse of RATE)
$JPPS,PERIOD,<Period in seconds (limited to 1.0, 0.5, 0.2, 0.1)
PPS Width can be controlled using
$JPPS,WIDTH,<width in usec>,[SAVE]
Note: $ JSAVE does NOT save the JPPS configuration so the desired 1PPS configuration
settings must be applied every time the receiver is powered on.
Each parameter must be individually saved as it is entered (by adding the optional SAVE at the
end of the command).
Event Marker Input
A GNSS solution may need to be forced at a particular instance, not synchronized with GNSS
time depending on the application, such as identifying features during a bathymetric survey.
The event marker input is 3.3 V CMOS active low with falling edge synchronization. The input
impedance and capacitance is higher than 10 kΩ and 10 pF, respectively, with a threshold of
lower than 0.7 V required to recognize the input.
Grounds
You must connect all grounds together when connecting the ground pins of the H220. These are
not separate analog and digital grounds that require separate attention.
Refer to
Table 2-2 for pinout ground information for the H220.
Speed Radar Output
Note: Speed radar output is not essential to normal receiver operation. Do not connect these pins
if you do not need this function.
Note: Event marker input is typical of most GNSS boards but not essential to normal
receiver operation. Do not connect this pin if you do not need this function.