Young Compass / Serial Interface 32400 - Manual (Page 3)

Page 2
32400-90
The full duplex RS-232 connection may transmit and receive serial data
at the same time.
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, trans-
mission 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 predeter-
mined 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.
4.2 SERIAL COMMANDS
Serial commands configure operating parameters and perform
calibrations.
While most W1 JUMPER settings configure the 32400 to use pre-
determined parameters, the SOFTWARE mode allows operational
parameters to be uniquely configured by serial commands. The
parameters are retained even when power is removed.
Commands may be sent using a PC and simple communications
programs such as HyperTerm or any other properly configured
serial device. All commands that begin with CMD must end with a
carriage return (ASCII 13).
Commands may be sent at any time but it may be more conve-
nient to pause 32400 serial output. This is especially necessary
with half-duplex RS-485 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
X Alternative command to enter OPERATE mode
3xESC Alternative command to PAUSE
FORMAT determines serial output format.
OUTPUT RATE determines the rate at which serial data strings
are sent from the 32400.
POLL CHARACTER sets the unique polling address for the
32400. Any single alphanumeric character may be used.
BAUD RATE selects one of several preset baud rates. If you
change baud rate while connected, your external device must
also be changed in order to continue communicating with the
32400.
REPORT PARAMETER SETTINGS shows the current state of
Output 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 con-
struction 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 war-
ranty 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.
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