OXTS xOEM500, Руководство по интеграции оборудования

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Oxford Technical Solutions Ltd www.oxts.com Page 15 of 22
Connector specifications
Power
The power supply input for the xOEM is 10
–31 V DC.
PPS
The 1PPS output signal is output from the primary GNSS receiver when a valid solution is found. The
output is a low-voltage TTL 3.3 V output where 0.8 V or less is low and 2.0 V or more is high.
1PPS input from an external source is 3.3 V low-voltage TTL, but tolerant of up to 5 V.
Serial
All 3 Serial connections adhere to standard voltages for RSR232 (±5 V).
Digital IO
All Digital IO connections are LVCMOS.
When configured as an input, the triggers see less than 0.8 V as low and more than 2.4 V as high.
The input range should be kept between 0 V and 5 V. The inputs have pull-up resistors so they can
be used with a switch or as a CMOS input. The resistors are 10 kΩ and pull-up to 3.3 V.
When configured as an output, the triggers have 0.8 V or less as low and 2.4 V or more as high. The
“slow trigger” pulse width is 1 ms. Slow triggers are used when the output rate is lower than the
periodic output of the INS e.g. less than 100 Hz on a system configured to run the navigation engine
at 100 Hz.
Output triggers can be also be output using a feature known as “fast triggers”. Fast triggers are used
when the output rate is higher than the periodic output rate of the INS, e.g pulse per metre rate is
higher than 100 Hz on a system configured to run the navigation engine at 100 Hz. The timing
accuracy of fast triggers is not as precise as slow triggers.
The odometer input requires less than 0.8 V for a low pulse and more than 2.4 V for a high pulse.
Limited protection is provided on this input, however the input voltage should not exceed 12 V.
Antennas
The xOEM500 GNSS modules receive L1 GPS signals at a nominal frequency of 1575.42 MHz, and
can receive L1 GLONASS signals at 1602.0 MHz. Antennas used with the xOEM500 must be capable
of tracking this signal for correct operation.
The xOEM550 GNSS modules receive L1 and L2 GPS signals at a nominal frequency 1575.42 MHz
and 1227.60 MHz respectively, and can receive L1 and L2 GLONASS signals spanning either side
from 1602.0 MHz and 1246.0 Hz respectively. Antennas used with the xOEM550 must be capable of
tracking these signals for correct operation.
The total preamplifier gain (minus cable and interconnect losses) must not exceed 50 dB. The total
antenna noise figure should be below 3 dB.
When using the xOEM in a dual antenna configuration, it is recommended to use the same type of
antenna with the same cable lengths for both the primary and secondary receivers.