beautypg.com

2 sensor configuration, Sensor configuration, Degrees – Campbell Scientific Open Path Eddy Covariance (OPEC) User Manual

Page 16

background image

OPEC Open-Path Eddy-Covariance System

Wind Vane

Wind Vector

Y

X

North

FIGURE 3-2. Compass coordinate system, compass wind direction is

140 degrees

3.1.2 Sensor Configuration

The IRGASON communicates with Campbell Scientific dataloggers using a
digital communication protocol called Synchronous Device for Measurement
(SDM). Each sensor connected to the SDM bus has a unique address. A
maximum of 15 addresses are allowed by the protocol and each sensor must
have a unique SDM address.

Do not use SDM address F (15) because it is reserved for
use with the Group Trigger instruction.

CAUTION

The IRGASON is shipped from the factory is set with a default SDM address
of 1. This address is set in software and can be changed using the software
DevConfig or ECMon and a USB cable. DevConfig is sensor/peripheral
support software shipped with LoggerNet. ECMon is PC support software
shipped with the IRGASON and is also available in the downloads section
online at

www.campbellsci.com

.

The program sets the IRGASON bandwidth to 20 Hz. The instrument delay is
a function the bandwidth setting and is automatically computed by the
datalogger program. To use a bandwidth other than 20 Hz, change the program
constant “BANDWIDTH” to the appropriate value. For more information on
IRGASON bandwidth and delay see the IRGASON manual.

The settings are sent to the IRGASON each time it is powered on
and only if connected to the datalogger via SDM. The settings
are not saved onto the IRGASON’s non-volatile memory.

NOTE

8