OXTS Survey+ v3, Руководство пользователя

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distance interval defined by the PPM settings. At the same moment the trigger signal is
output, a position measurement will be internally generated and logged alongside the regular
measurement data. To generate a real-time message in relation to the camera trigger, it is
necessary to select the ‘Output on camera trigger option’ on the Ethernet configuration
window.
Wheel speed input
The wheel speed 1A input (J5-3) accepts TTL pulses from an encoder on a single wheel.
An encoder from a gearbox should not be used, and simulated TTL pulses (e.g. converted
from the vehicle CAN bus) should not be used either. The timing of the wheel speed input
pulses is critical and nothing should cause any delay to them.
The also accepts signals from quadrature wheel speed sensors. When using
quadrature sensors, connect one channel from the quadrature sensor to wheel speed 1A,
and the other to wheel speed 1B input (J5-5). The odometer input should be configured as
per a normal wheel speed sensor – the RT1003 will automatically detect the use of the
quadrature sensor.
The wheel speed 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 port, however the input voltage should
not exceed 12 V.
Wheel speed input signal characteristics:
• 0 V to 12 V
• low < 0.8 V
• high > 2.4 V
The wheel that is used should not steer the vehicle. The will assume the wheel
travels straight.
IMU sync output pulse
The IMU (inertial measurement unit) sync output pulse is a 100 Hz 200 Hz or 250 Hz
output pulse synchronised to the IMU sample time. The output has a duty cycle of
approximately 50% and the falling edge is synchronised to the sample file of the data from
the IMU.
The IMU is already synchronised to GPS time so one of the pulses each second will line
up with the 1PPS output. This allows other systems to sample based on the timing of the
.