METEOROLOGICAL INSTRUMENTS
INSTRUCTIONS
SERIAL INTERFACE
MODEL 32400
R.M. YOUNG COMPANY 2801 AERO PARK DRIVE, TRAVERSE CITY, MICHIGAN 49686, USA
TEL: (231) 946-3980 FAX: (231) 946-4772 WEB: www.youngusa.com
P/N: 32400-90
REV: O032410
MODEL 32400
SERIAL INTERFACE
SPECIFICATIONS*
Win d Speed Input:
Sensor Type: AC Frequency Generator
Sensitivity: 50mV p-p at 10Hz
Range: 0-2000 Hz
Win d Direction Input:
Sensor Type: Potentiometer
Range: 0-5000mV = 0 to 355 degrees
Excitation: 5000mV (limited to 5 mA)
3.1 SIGNAL INPUTS
The 32400 has two special inputs for wind speed and direction from
YOUNG sensors and four voltage input channels for connection to other
meteorological instruments like temperature, humidity, and barometric
pressure sensors. For best performance, sensors should be installed
within 3m (10ft.) of the 32400.
Measurements from the voltage input channels are converted to numerical 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
If PRECIP or PRECIP POLLED serial output formats are active, VIN4 is
used to count tipping bucket precipitation sensor tips.
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° 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
*Specications subject to change
1.0 INTRODUCTION
The Model 32400 SERIAL INTERFACE measures wind speed and direction signals from YOUNG sensors and signals from four general purpose
voltage inputs. The voltage inputs may be used with YOUNG temperature, humidity, and barometric pressure sensors. One of the voltage
inputs may also be used with 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 32400 produces standard NMEA serial output sentences. Calibrated voltage outputs for wind
speed and direction are also provided when the 32400 is connected to a
YOUNG wind sensor.
2.0 INSTALLATION
The 32400 is supplied in a weather-resistant enclosure with a mount-
ing adapter that ts 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.
3.0 OPERATION
Operation begins automatically when power is applied. Jumpers congure the 32400 for common output formats.
Please refer to SERIAL FORMAT DIAGRAM and WIRING DIAGRAM in
the Appendix for additional details.
3.2 JUMPERS
W1 JUMPERS A, B, and C, determine serial output format. Jumper
congurations and associated output format are listed below: 1 signies
that jumper is installed, 0 signies that jumper is omitted. See the SE-
RIAL FORMAT DIAGRAM in the Appendix for more details.
A B C SERIAL OUTPUT FORMAT
0 0 0 ASCII Ouput
0 0 1 Polled ASCII
0 1 0 NMEA1
0 1 1 NMEA2
1 0 0 RMYT
1 0 1 PRECIP
1 1 0 PRECIPT POLLED
1 1 1 SOFTWARE Mode
ASCII and RMYT formats force the serial baud rate to 9600. NMEA
formats force the baud rate to 4800.
ASCII and POLLED ASCII are general purpose outputs that may be
used with the YOUNG 26800 or devices that can communicate serially.
NMEA outputs are generally for marine applications. RMYT is a proprietary format for use with the YOUNG Wind Tracker.
PRECIP and PRECIP POLLED congure VIN4 as a special input to
count tipping bucket precipitation gauge switch closures. (Requires a
10K ohm resistor from VIN4 to EXC terminal.)
SOFTWARE mode allows output format and other parameters to be set
using serial commands. Please see section 4.0 SERIAL COMMUNICATION and the SERIAL FORMAT DIAGRAM for more information.
W2 & W3 JUMPERS determine output connection type. Only one
connection type may be used at a time. Please refer to the WIRING
DIAGRAM in the Appendix for jumper location and connection details.
JUMPERS OUTPUT TYPE
VOUT Calibrated output for wind speed and direction
OUT1 0-5000mV = 0-100 m/s Wind Speed
OUT2 0-5000mV = 0-360 degrees Wind Direction
232 RS-232 full duplex serial
485 RS-485 half duplex serial
4.0 SERIAL COMMUNICATION
The 32400 uses either full-duplex RS-232 or half-duplex RS-485 signals
for serial communication. RS-232 is the most simple and operates up
distances of 30m (100ft). The RS-485 option is prefered in electrically
noisy environments, in applications where multiple units must be
networked, or in NMEA marine applications where RS-485 signals are
required.
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The full duplex RS-232 connection may transmit and receive serial data
at the same time.
OUT PUT RATE dete rmines the rate at which seri al data str ings
are sent from the 324 00.
The RS-485 connection is half-duplex meaning the unit cannot transmit
and receive at the same time. The 32400 internally manages the switch
between modes.
Many applications require the 32400 to transmit only. However, RS-485
applications that require polling the 32400 or sending commands to it
require that the externally connected serial devices must be capable of
managing its own half-duplex switching from transmit to receive.
At low baud rates with proper cable installation and connections, transmission distances up to 7km (4mi) are possible using RS-485.
Baud rates of 1200, 4800, 9600, 19.2K, and 38.4K baud are available.
Most jumper-selected output formats force the baud rate to a predetermined value. All serial signals use 1 start, 8 data, and 1 stop bit. Any
externally connected serial device must be set to the same baud rate as
the 32400.
4.1 POLLING
When the serial output format is ASCII POLLED or PRECIP POLLED,
the 32400 sends data only when it receives a serial polling command:
Ma!
where ‘a’ is the unique address of the unit. The default address is ‘A’ but
any alphanumeric character may be used (see POLLING CHARACTER
in section 4.2 SERIAL COMMANDS).
See the SERIAL FORMAT DIAGRAM for details on ASCII POLLED
data format.
POL L CHARAC TER sets th e unique polling a ddress for the
32400. Any sing le alphanumeric character may be used.
BAUD RATE selects one of several p reset baud rates. If you
change baud rate whil e connected, your external de vice must
also be changed in or der to continue communicating with the
32400.
REPORT PARAMETER SET TINGS shows the current state of
Out put Format, Output Rate, and Poll Character.
5.0 MAINTENANCE
The 32400 requires no maintenance in normal use. Periodic inspection
is recommended to verify correct operation.
6.0 WARRANTY
This product is warranted to be free of defects in materials and construction for a period of 12 months from date of initial purchase. Liability
is limited to repair or replacement of defective item. A copy of the warranty policy may be obtained from R. M. Young Company.
7.0 CE COMPLIANCE
This product complies with European CE requirements for the EMC
Directive. Please note that shielded cable must be used.
4.2 SERIAL COMMANDS
Serial commands confi gure operating par ameters and perform
calibrations.
Whi le most W1 JUMPER settings co nfigure the 32400 to use predetermined parameters , the SOFTWARE mode allows operational
parameters to be uniq uely configured by serial com mands. The
parameters are retain ed even when power is removed .
Commands may be sent using a PC and simple communi cations
programs such as Hype rTerm or any othe r properly configured
serial device. All commands that begin with CMD must en d with a
carriage return (ASCI I 13).
Commands may be sent at any time but it may be mor e convenient to pause 32400 serial output. This is especially necessary
with half-duplex RS-4 85 communication.
Command Description
CMD100 OPERATE
CMD110 PAUSE
CMD210 n FORMAT 0 ASCII
1 ASCII POLLED
2 NMEA (KNOTS, DIR)
3 NMEA (KNOTS, DIR, TEMP, RH, BARO
4 RMYT
5 PRECIP
6 PRECIP POLLED
9 DIAGNOSTIC
CMD220 n OUTPUT RATE (0=15Hz, 1=0.1Hz, 2=2Hz)
CMD230 c POLL CHARACTER (0-9, A-Z)
CMD240 nn BAUD RATE
12=1200, 48=4800, 96=9600, 192=19200, 384=38400
CMD900 REPORT PARAMETER SETTINGS
Declaration of Conformity
R. M. Young Company
2801 Aero Park Drive
Traverse City, MI 49686 USA
Model 32400 SERIAL INTERFACE
The undersigned hereby declares on behalf of R. M.
Young Company that the above-referenced product, to
which this declaration relates, is in conformity with the
provisions of:
Council Directive 2004/108/EC (December 15, 2004)
on Electromagnetic Compatibility
David Poinsett
R&D Manager
X Alternative command to enter OPERATE mode
3xESC Alternative command to PAUSE
FOR MAT determine s serial output format.
32400-90
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