Campbell Scientific AP200 CO2/H2O Atmospheric Profile System - Manual (Page 49)

AP200 CO
2
/H
2
O Atmospheric Profile System
BATT_LOWLIMIT as appropriate to protect his battery. If AC main power
and an AC/DC adapter are used, the limit may be left at 9.7 V.
BATT_DEADBAND: This variable, along with BATT_LOWLIMIT,
determine when the AP200 will restart after an automatic power shutdown.
The AP200 will not restart until the supply voltage batt_volt reaches at least
BATT_LOWLIMIT + BATT_DEADBAND. The purpose of the deadband
(the gap between the shut-down voltage and the turn-on voltage) is to protect
the AP200 from repeated power cycles when the battery voltage is very near
the limit. BATT_DEADBAND must be zero to 10.0 V. The default is 1.0 V.
5.4.2 Compile Switches
The AP200 program defines three constants that are used as compile switches.
These constants define which optional values are to be stored in the output
tables.
MaxLevels: MaxLevels defines the maximum number of profile levels. The
default is eight, but it may be set to the actual number of levels used (four to
eight) to avoid null data for unused levels in the IntAvg output table. The
number of levels measured is determined by system configuration variable
LEVELS_USED.
SaveAll_diagnostics: If constant SaveAll_diagnostics is set to False (the
default), the RawData output table will contain only those values required for
normal operation. If it is set to True, the AP200 will save some additional
diagnostic values in output table RawData.
N_AirTemps: Constant N_AirTemps determines the number of 107-L
temperature sensors to measure. It may be from one to eight, or zero, which is
used to disable air-temperature measurements. The default is zero. See
Appendix E, Temperature Profile, for more details on adding a temperature
profile measurement.
5.5 Starting and Stopping the Sequence
In normal operation, the AP200 will automatically cycle through the profile
inlets. If configured for automatic zero/span, it will periodically run the
calibration (zero/span) sequence and then return to the profile sequence. The
user may stop the sequence to control the valves manually and then restart the
sequence using the public variables described below. If any of the variables
that control the valve sequence are edited, the sequence must be stopped and
restarted before changes will be in effect. The following public variables allow
the user to start and stop the sequence and to control the valves manually.
seq_ACTIVE: Reports whether the AP200 is controlling the valves (True) or
not (False). If seq_ACTIVE = False, the valves can be controlled manually.
This variable is for information only; its value cannot be directly changed by
the user.
STARTsequence: Allows the user to start the sequence. Set this variable to
True to start the automatic valve switching sequence. The AP200 will change
valve_number to 1 and wait until it can synchronize the valve sequence to the
real-time clock. This may take up to two minutes (see Appendix F, Valve
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