Campbell Scientific CPEC200 Closed-Path Eddy-Covariance System - Manual (Page 55)

Appendix A. CPEC200 Diagnostics
because the EC100 is not powered, or the SDM cable from the
datalogger to the EC100 is not connected.
• ERROR: No EC155 detected - Check EC155 connections to EC100 is
displayed if diag_irga = −1 (all diagnostic bits are set). This usually
means the EC155 sensor head is not connected to the EC100.
• If bit 9 of diag_irga is set, this indicates the EC155 has been powered
down. There are multiple possible causes and each has a different
message reported in irga_status:
o ERROR: IRGA is OFF - Check BattVolt is displayed if
BattVolt_OK = False. This usually means the EC155 has
been powered down by the CPEC200 because the battery
voltage has dropped below the shutdown limit.
o ERROR: IRGA is OFF - Check source_tmpr is displayed if
BattVolt_OK = True and bit 7 of diag_irga is set. This
usually indicates the EC155 has powered itself down because
the internal temperature, source_tmpr, is outside its
operating range. The EC155 will power itself off if
source_tmpr rises above 55°C, and will not turn back on
until the temperature drops to 50°C. At cold temperatures,
the EC155 will power off at –35°C and back on at –30°C.
o ERROR: IRGA is OFF is displayed if the EC155 is powered
down for an unknown reason.
• IRGA is starting up is displayed if bit 3 of diag_irga is set. This
normally indicates the EC100 has just been powered up or the EC155
has been turned on. It may take a few minutes for the IRGA to start
up and report data.
• ERROR: diff_press problem - Check intake filter is displayed if bit 23
of diag_irga is set. Normally, this indicates the EC155 intake filter
has plugged, which causes a pressure drop in the EC155 greater than
the differential pressure sensor’s ± 7 kPa range.
• ERROR: CO2 signal is too low - Check EC155 windows is displayed
when the CO
2
signal level is below 0.8. This normally indicates the
EC155 windows have become dirty and should be cleaned.
• ERROR: H2O signal is too low - Check EC155 windows is displayed
when the H
2
O signal level is below 0.8. As with CO
2
signal level, this
normally indicates the EC155 windows have become dirty and should
be cleaned.
• ERROR: IRGA problem - Check diag_irga is displayed when some
other bit is set in diag_irga. See the EC155 user manual for further
troubleshooting suggestions.
sonic_status
Public variable sonic_status gives the status of the sonic anemometer and is
based on the diagnostic word from the CSAT3A ( diag_sonic).
• Sonic is OK is displayed if diag_sonic = 0. This means the CSAT3A
has detected no problems.
• ERROR: No data from sonic - Check EC100 power and
communication is displayed if diag_sonic = NAN. This indicates the
EC100 does not respond to the datalogger’s request for data, usually
because the EC100 is not powered, or the SDM cable from the
datalogger to the EC100 is not connected.
• ERROR: No CSAT3A detected - Check CSAT3A connections to
EC100 is displayed if diag_sonic = −1 (all diagnostic bits are set).
A-3