Young Ultrasonic Anemometer Heated Model 85004 - Manual (Page 7)

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85004-90
aC! a00102
aC1! a00102
aCC! a00102
aCC1! a00102
aD0! a+www.w_ddd
a±uu.uu±vv.vv
where:
a = Sensor address
ddd = Wind direction (degrees)
www.w = Wind speed (selected units)
±uu.uu = U-axis wind speed (m/s)
±vv.vv = V-axis wind speed (m/s)
= CRC checksum (only where requested)
= Carriage return, line feed (ASCII 13, 10)
5.3.7 ADDITIONAL SDI-12 INFORMATION
The 85004 sensor conforms to all aspects of the SDI-12 version 1.3
protocol and will respond to the additional commands listed below.
For further information on the SDI-12 protocol, visit www.sdi-12.org
on the web.
SDI-12 SENSOR
COMMAND RESPONSE
?! a
a! a
aI! a13 YOUNG 85000 v1.00
aAb! b
a = Sensor address
b = New sensor address
aV! a0004
Retrieve V data with D command.
Response listed next.
aD0! a+sc+fmt+thresh+damp
a = Sensor address
sc = sample count 0-99
fmt = SDI-12 format 0=CONT, 1=STANDBY
thresh = Polar threshold (cm/s)
damp = Damping factor
aX1nn! None. nn = Sample count 00 or 03-31
aX2n! None. n = SDI-12 format 0=CONT, 1= STANDBY
aX3nnn! None. nnn = Polar threshold 0-999 cm/s
aX4nn! None. nn = Damping factor 0-99
5.4 LOW POWER OPERATION
The following low power options are available only when heaters are
disabled. Heaters may be enabled or disabled using the 2DSETUP
program.
Average current consumption with default settings is about 150
mA. This configuration uses no power conservation and enables
all features even though they may not be used. Average current
consumption with once-per-second ASCII serial output and typical
power conservation settings is about 30 mA. This is suitable for many
low power applications.
To reduce current consumption further, additional strategies must
be employed. These include disabling unused outputs, using polled
serial operation, increasing the delay between samples, and limiting
the sample count to the minimum optimal number. Faster baud rates
reduce power by limiting transmit duration.
Lowest power consumption is realized with SDI-12 output format.
However, this requires use with an SDI-12 compatible data logger.
With SDI-12, the average current consumption may easily be reduced
to less than 12 mA during measurements and 320 uA in standby.
6.0 SETTING OUTPUTS AND OPERATING
PARAMETERS
6.1 SETUP WITH YOUNG 2DSETUP PROGRAM
(RECOMMENDED)
The 2DSETUP program supplied with the sensor provides an easy
method for checking and changing operating settings in the model
85004. Simply install the program on a Windows PC. Follow the
instructions to get the current settings from the sensor, change set-
tings, and send the new settings to the sensor.
6.2 SETUP USING ANOTHER COMMUNICATIONS PROGRAM
If desired, a serial communications program like HyperTerminal may
be used. Parameters are set using simple commands. A limited
number of parameters may also be set using SDI-12 commands.
For serial communication, the sensor and communication program
must be at the same baud rate and the sensor must be properly con-
nected. The default baud rate is 9600 but may be set to 1200, 4800,
or 38400. Either RS-232 or RS-485 full duplex may be used. Set
hardware handshaking to 'NONE' in your communications program
and use 1 start, 8 data, 1 stop bit.
Except for SDI-12 format, the sensor must be in COMMAND MODE
in order to set parameters. COMMAND MODE is activated by sending
three ESC characters (ASCII 27) in quick succession while the sensor
is running. To signify that the sensor is ready to accept commands,
a '>' prompt character will appear.
If the prompt does not appear after receiving three ESC characters,
re-check the wiring and communication program setup. If the sen-
sor baud rate is unknown, try sending the ESC characters at each
of the four available baud rates (1200, 4800, 9600, and 38400). It
is also possible that parameters have been set to purposefully dis-
able RS-232 or RS-485 connections. If this the case, the following
method must be used.
In order to provide access under all conditions, the sensor always
begins operation at power up with serial communications set to
38400 baud and RS-232 connections enabled. Immediately after
power up, there is a four second time window in which to send the
ESC characters and enter COMMAND MODE.
To use this feature, set a serial communication program (such as
HyperTerminal) to 38400 baud with no handshaking. Apply power
to the sensor (the sensor must be off for about 30 seconds before
power up). The sensor will transmit *** (three asterisk characters)
immediately after power up. Now send the three ESC characters.
The COMMAND MODE '>' prompt should appear.
6.3 COMMAND OVERVIEW
At the prompt, type '??' to display a list of available commands
and their format. Type 'RPT' to report current settings. (Note that
some values in the list cannot be set by the user.) Commands are
case sensitive and the exact format must be used. For example, the
SET02nn command requires two digits for the serial format code.
If you send SET023 instead of SET0203, the sensor will reject the
command and indicate an error. Terminate all commands with a
carriage return (ASCII 13). In HyperTerminal, do this by pressing
the ENTER key.
When RMYT, NMEA, or SDI-12 serial format is selected, some