LI-COR LI-710 - The XT (Trigger) Command; Default Settings

Section 3. Overview of SDI-12 and the LI-710
Use the XT command every 30 minutes to instruct the LI-710 to begin recording for
a 30-minute measurement period. This ensures that data are aligned in time for
every measurement period, and it prevents drift in the sampling period.
The XT (trigger) command
If you are using the trigger command, results are updated 30 minutes after the trig-
ger is received. When you send the trigger command, the LI-710 starts a new meas-
urement sequence. If a trigger is received once but not received again, fluxes will be
computed in hourly intervals thereafter. Once a trigger is supplied, another trigger
command is required to start the next measurement interval. We recommend send-
ing the trigger command and retrieving data once every 30 minutes.
Default settings
All LI-710s leave LI-COR with address 0. It can be changed with the A command if
needed.
To communicate with the sensor, you will program the datalogger to measure the
sensor output every 30 minutes. Send the sensor the M command to collect data. M0
collects the basic data set. M1, M2, or M3 collect different data sets. The LI-710 only
requires the M commands, but you can use them with the XT command to trigger
each measurement period. The contents of each packet that is returned by the
Mcommands are defined in Data and variables on page7-1.
Detailed instructions for common dataloggers are in following sections:
l
Using an SDI-12-to-USB translator on page4-1.
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Connecting to Campbell Scientific dataloggers on page5-1.
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Connecting to the Sutron 9210 datalogger on page6-1.
3-2 LI-710 Evapotranspiration Sensor Instruction Manual