Young Barometric Pressure Sensor Model 61302V - Manual (Page 2)

3.0 INSTALLATION
The sensor operates over a temperature range of -40°C to
+60°C and must remain dry.
Electrical connections are made with the 5-position
terminal plug included with the sensor. Jumper settings
may be used to select operating options. Access jumpers
by loosening two screws in the sensor enclosure and
removing the cover. See Appendix A for wiring details and
jumper settings.
If changed from the standard configuration, please note
that the software Vout Scale parameter must be set to
agree with the hardware Voltage Output Scale jumper (P3)
in order to achieve calibrated output.
4.0 OPERATION
Operation begins approximately 1 second after power is
applied. Output will appear after a delay determined by
the number of samples averaged and the output rate. With
default values (1.8 Hz output and 10 samples averaged),
outputs will begin after an initial 5 second delay then
remain continuous at the 1.8 Hz rate. Parameters for
output rate and number of samples averaged may be
changed using software commands.
4.1 VOLTAGE OUTPUT
Hardware jumpers and software parameters determine
voltage output operation. Appendix A shows jumper
configurations.
Both P4 jumpers must be in position B for voltage output.
Jumper P3 sets the Voltage Output Scale to either
0-5000 mV or 0-2500 mV. Please note that jumper P3
must agree with the software Vout Scale parameter in
order to achieve calibrated output.
The voltage output scale may be mapped to any part of the
500 to 1100 hPa pressure range using the VOUT HI and
VOUT LO software parameters. The standard setting maps
0 to 5000 mV with 500 to 1100 hPa. With this setting:
hPa = 0.12 * mV + 500
Effective resolution is about 0.15 hPa
Better effective resolution may be achieved by mapping
the voltage output to a narrower range of pressure with
the VOUT HI and VOUT LO parameters. For example, with
VOUT LO set to 950 hPa and VOUT HI set to 1050 hPa
and the VOUT Scale set to 0-5000 mV:
hPa = 0.02 * mV + 950
Effective resolution is about 0.025 hPa
Please see section 4.3 below for details on changing the
VOUT HI and LO parameters.
With jumper P4 configured for voltage output, a special
TRIG input may be used to control barometer power. When
TRIG=0V, all processes cease and power consumption is
reduced to 1.4uA. When the voltage on TRIG > 1.8V (or
left floating), normal operation resumes with a powerup
reset. The TRIG input connection is optional. It may be
connected to +PWR or left floating.
4.2 SERIAL OUTPUT
Jumper settings and software parameters determine
RS-232 serial communication format. The Appendix A
Wiring Diagram shows jumper locations and function.
1.0 SPECIFICATIONS
Pressure 500 to 1100 hPa standard range
Digital Accuracy* 0.2 hPa (25°C)
0.3 hPa (-40°C to +60°C)
Analog Accuracy** 0.05% of analog pressure range
Analog Temperature
Dependence**
0.0017% of analog pressure range
per °C (25°C reference)
Long Term Stability: 0.2% FS per year
*Defined as ±1 standard deviation from NIST-traceable
pressure reference in clean, dry air. Includes non-
linearity, hysteresis, repeatability, and calibration
uncertainty.
**Defined as ±1 standard deviation from ideal analog
output. Total analog output accuracy is the root sum
square of digital accuracy, analog accuracy, and
analog temperature dependence.
Output Rate 1.8 Hz (max) to 1 per minute
Voltage Output
0 to 5000 mV (standard)
0 to 2500 mV
12-bit resolution (1 in 4000)
Selectable pressure range:
500 to 1100 hPa (standard)
Serial Output Full duplex RS-232
1200 to 38400 baud
Continuous ASCII text
Polled ASCII text
NMEA
0.01 hPa resolution
Supply Voltage 7 to 30 VDC
2.8 mA with Vout (standard)
1.4 uA shutdown (Trig=0V)
7 mA with serial I/O
Case Fiber-reinforced thermoplastic
Weight 44 g (1.5 oz)
2.0 INTRODUCTION
MODEL 61302V Barometric Pressure Sensor is a
versatile electronic barometer featuring high accuracy,
low power, wide operating temperature range, and
calibrated voltage output or RS-232 serial data I/O.
Low power consumption and wide temperature range
make the 61302V ideal for remote applications using
battery or solar power.
Full scale voltage output may be set to span any portion
of the 500 to 1100 hPa operating range. RS-232 serial
I/O options include continuous or polled ASCII text output
or NMEA marine output. The sensor is supplied with the
following standard configuration:
Voltage output
0 to 5000 mV = 500 to 1100 hPa
10 samples averaged
1.8 Hz update rate
P1 A/B/C sets output format, baud rate, output rate, and
averaging.The table below summarizes P1 configurations.
P3 A/B sets RS-232 hardware function. AUTO (A) enables
RS-232 hardware when valid standard RS-232 signals
are present at RX and TX. When not present, the RS-232
hardware is disabled to save power. FIXED (B) enables
RS-232 hardware at all times so it can be used with some
non-standard RS-232 signals.
P4 A/B configures the terminal connections for RS-232.
Both jumpers must be in position A for RS-232 serial
communication.
Format Description
Continuous ASCII
Text
(standard) 9600 baud
10 sample average
1.8 Hz output
Polled ASCII Text 9600 baud
10 sample average
Output when polled
Marine NMEA 4800 baud
10 sample average
1Hz output
Software Output parameters determined
by software settings
Note that NMEA output is normally specified to work on
RS-422 and RS-485 networks. The NMEA output here
conforms to the standard data format but the electrical
connection uses RS-232 signal levels.
In POLLED ASCII mode, the unit sends data only after
receiving a poll command. The poll command is Ma! where
‘a’ is the address value. The standard address is ‘0’ (ASCII
48) for a poll command of M0! Please see section 4.3 for
details on changing the poll address.
Standard baud rate is 9600 but any of several available
baud rates between 1200 and 38400 may be used.
4.3 SOFTWARE COMMANDS
Software commands sent via serial communication may
be used to set operational parameters. The sensor must
be configured for serial communication and connected
to a PC or other compatible device using a program like
HyperTerm.
New settings are stored in temporary memory and
must be burned to flash with command CMD420 to be
retained.
Note that the P1 jumper must be configured for
SOFTWARE format to alter baud rate, sample average
count, and output rate parameters.
Although the sensor may receive commands at any
time, measurement output may be paused by sending
three ESC (ASCII 27) characters or CMD300 1. While
paused, COMMAND mode is indicated by a “>” prompt.
All commands must be terminated with a carriage return
CR (ASCII 13).
Use “?” to list available commands as shown below.
> ?
Y O U N G 6 1 3 0 0 S E R I E S B A R O M E T E R V 2 . 0 3
- - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - -
C M D 1 0 0 n O U T P U T P E R I O D ( 0 - 6 0 s e c )
C M D 1 0 5 n A V G S A M P L E C O U N T ( 0 - 3 2 )
C M D 1 1 0 n O U T P U T F O R M A T
( 1 = A S C I I 2 = P O L L E D 3 = N M E A 4 = R A W 5 = D I A G )
C M D 1 2 0 n M U L T I P L I E R ( 1 0 0 0 0 = 1 . 0 0 0 0 )
C M D 1 2 5 n O F F S E T ( h P A x 1 0 0 )
C M D 1 3 0 n S E A L E V E L C O R R E C T I O N ( h P A x 1 0 0 )
C M D 1 4 0 n V O U T R A N G E H I ( 5 0 0 - 1 1 0 0 )
C M D 1 4 2 n V O U T R A N G E L O ( 5 0 0 - 1 1 0 0 )
C M D 1 4 4 n V O U T S C A L E ( 2 = 2 . 5 V 5 = 5 V )
C M D 1 5 0 c P O L L A D D R C H A R
C M D 1 6 0 n B A U D R A T E ( 3 8 4 0 0 , 9 6 0 0 , 4 8 0 0 , 2 4 0 0 , 1 2 0 0 )
C M D 3 0 0 n 1 = S T O P , 2 = R U N
C M D 3 1 0 n F O R C E V O U T ( 0 - 5 0 0 0 F U L L S C A L E )
C M D 4 0 0 n 1 = R P T T E X T , 2 = R P T C O D E O N L Y
C M D 4 1 0 G E T C A L T A B L E
C M D 4 2 0 S T O R E S E T U P P A R A M E T E R S
>
CMD100 n sets output period in seconds. When set to
zero, the output rate is about 1.8 per second.
CMD105 n sets the average sample count. Higher
sample count yields more stable readings but will
lengthen the startup delay.
CMD110 n sets output format. RAW and DIAG settings
are for factory use only.
CMD120 n sets the output multiplier. 10000 represents
1.0000
CMD125 n sets the output offset in hPa x 100
CMD130 n sets the sea level correction in hPa x 100
=[
P
unadjust
*(
Mult / 10000
)] + [(
Offset
/
100
) + (
Correction
Sea Lvl
/
100
)]
CMD140 n sets the Vout Pressure Range HI
CMD142 n sets the Vout Pressure Range LO
Vout Pressure Range HI must be greater than Vout
Pressure Range LO
CMD144 n sets the Vout Scale. 2 = 0 to 2500 mV. 5 =
0 to 5000 mV. This parameter setting must agree
with the physical P3 jumper position to achieve
calibrated voltage output.
CMD150 c sets the poll address character. Any ASCII
character from ‘0’ (ASCII 48) to ‘z’ (ASCII 122) may
be used.
CMD160 n sets the baud rate. Acceptable values are
38400, 9600, 4800, 2400, and 1200. Note that
the baud rate change occurs immediately after
the command is received. Therefore, in order to
continue communicating, the serial communication
program that issued the command must also change
to match.
CMD300 n causes the sensor to pause or resume
measurement. 1 = Stop, 2 = Run.
CMD400 n causes the sensor to issue a report
summarizing parameter settings.
1 = RPT text
2 = RPT code only
CMD410 retrieves the internal calibration table. This is
for factory use only.
CMD420 burns new parameter settings to flash memory.
This step must take place to retain changes
otherwise parameters will revert to the previous
values at the next powerup.