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32500-90(S)
MODEL 32500
ELECTRONIC COMPASS
WITH SERIAL INTERFACE
SPECIFICATIONS
*
Compass:
Resolution:
0.5 degrees
Accuracy:
±2 degrees (rms)
Wind Speed Input:
Sensor Type:
AC Frequency Generator
Sensitivity:
50mV p-p at 10Hz
Range:
0-2000 Hz
Wind Direction Input:
Sensor Type:
Potentiometer
Range:
0-5000mV = 0 to 355 degrees
Excitation:
5000mV (limited to 5 mA)
Voltage Inputs (Auxiliary Sensor Inputs):
Resolution:
12-bit
VIN1 and VIN2
0-1000mV
VIN3 and VIN4
0-5000mV
Voltage Outputs:
OUT1
0-5000mV
0-100 m/s wind speed
OUT2
0-5000mV
0-360° true wind
direction
Serial Output:
Full duplex RS-232,
Half duplex RS-485 (2 mS turnaround)
1200, 4800, 9600, 19.2K, & 38.4K baud
8 data, 1 stop, no parity
Operating Temp:
-50°C to 50°C
Power:
11 to 30 VDC, 40 mA
Mounting:
1 inch IPS (1.34 inch actual diameter)
Size:
4.75” (12cm) H
0.87” (7.3cm) W
2.12” (5.3cm) D
*
Specifications subject to change
1.0 INTRODUCTION
The Model 32500 ELECTRONIC COMPASS measures magnetic head-
ing, wind speed and direction signals from YOUNG sensors, and signals
from four general purpose voltage inputs. Wind direction input may be
combined with compass measurements to obtain true direction. Voltage
inputs may be used with YOUNG temperature, humidity, barometric
pressure, and other sensors. One voltage input may be configured for
connection to a tipping bucket precipitation gauge.
Measurements are available in several serial data formats in either full
duplex RS-232 or half-duplex RS-485 signals. Both continuous and
polled serial outputs are available. When polled, up to 16 units can be
networked together. For marine applications the 32500 produces stan-
dard NMEA serial output sentences. Calibrated voltage outputs for wind
speed and direction are also provided when the 32500 is connected to a
YOUNG wind sensor.
2.0 INSTALLATION
The 32500 is supplied in a weather-resistant enclosure with a mount-
ing adapter that fits 1 inch IPS pipe (1.34 inch nominal diameter). When
used with the YOUNG Wind Monitor, the mounting adapter engages
the Wind Monitor orientation notch. Refer to the WIRING DIAGRAM for
electrical connection details and jumper settings.
It is important to install the 32500 so it remains level during operation.
This becomes increasingly important when used at northern and south-
ern latitudes far from the equator since progressively more of the earth’s
magnetic flux becomes vertical. By keeping the 32500 level at these
latitudes, the measurements will be free of the vertical flux influence and
remain accurate.
If possible, avoid installing the compass near magnetic devices or ma-
chinery. After installation, the compass must be calibrated to correct for
local magnetic conditions. If the compass is moved or its local environ-
ment changes significantly (machinery moved), the compass should be
calibrated again.
3.0 OPERATION
Operation begins automatically when power is applied. Jumpers config
-
ure the 32500 for common output formats.
3.1 COMPASS CALIBRATION
When the 32500 is operated for the first time, its internal compass must
be calibrated for local conditions. To calibrate the compass, please follow
the steps outlined below.
1. Remove cover from compass. Press and hold CALIBRATE button
for 5 seconds. The CALIBRATE indicator will begin to blink. Refer to
WIRING DIAGRAM to locate CALIBRATE button.
2. Slowly rotate vehicle on which compass is mounted. Steer vehicle in
a tight circle and make TWO complete revolutions. Each revolution
should take at least one minute. THE COMPASS MUST REMAIN
LEVEL DURING CALIBRATION.
3. After two complete revolutions, press and hold CALIBRATE button
until indicator stops blinking. Calibration is now complete. Calibration
parameters are retained when power is removed.
4. Replace cover. Use this procedure to recalibrate compass at any time.
Serial communication command may also be sent to start and stop the
compass calibration. Please see section 4.2 SERIAL COMMANDS for
details.
3.2 SIGNAL INPUTS
The 32500 has two special wind speed and direction inputs for YOUNG
sensors and four voltage input channels for connection to other meteo-
rological instruments like temperature, humidity, and barometric pres-
sure sensors. Two of the voltage input channels may also be configured
as alternative wind speed and wind direction inputs for sensors like the
Young 86xxx family. For best performance, sensors should be installed
within 3m (10ft.) of the 32500.
Measurements from the voltage input channels are converted to nu-
merical values (0-4000) and sent in the serial ASCII output string:
VIN1 and VIN2 full scale input is 1000mV DC, therefore:
Input millivolts = Serial output value / 4
VIN3 and VIN4 full scale input is 5000mV, therefore:
Input millivolts = Serial output value x 1.25
VIN3 and VIN4 may be configured as alternative wind speed and direc
-
tion inputs using CMD250 in SOFTWARE mode. Please see section 4.2
SERIAL COMMANDS.
Selecting PRECIP or PRECIP POLLED output formats will configure
VIN4 to count tips from a tipping bucket precipitation gauge.
