Campbell Scientific CPEC200 Closed-Path Eddy-Covariance System - Manual (Page 53)

Appendix A. CPEC200 Diagnostics
A.1 Overview
CPEC200 diagnostic information is available to the user in any of three
different formats: status text strings, status Boolean variables, and diagnostic
flags encoded as binary bits in integer variables. With these multiple avenues
of accessing the information, the CPEC200 diagnostics provide user-friendly
real-time troubleshooting, statistics on individual error conditions, and a
compact format for final storage tables.
A.2 Status Text Variables
There are several text-string variables that report the status of the CPEC200
system in real time. These are public variables that can be viewed onsite using
the datalogger display. They may also be viewed remotely via LoggerNet,
LoggerLink, or other applications if a communication link is available. The
status text variables are not as comprehensive as the diagnostic flags, but they
provide troubleshooting help for most of the issues that are likely to arise and
can guide the user to the more advanced diagnostic information.
Status variables are not generally saved in the output tables because they take
too much storage space. Each of these variables is described below.
latest_note
Public variable latest_note shows the latest message written to the
message_log table. The message_log table stores a record that includes a text
message as well as several variables that describe the state of the system when
the record is written. It notifies the user of a significant event, such as a change
to a configuration variable or events related to a zero/span sequence. After one
minute the text in latest_note is marked as old, but is still displayed. See
Appendix C, Output Variables, for more information on the message_log
table.
mode_status
Public variable mode_status describes the basic operating state of the
CPEC200. It correlates with Boolean variable EC_mode. If EC_mode =
True, then mode_status will be Normal EC mode. If EC_mode = False,
multiple messages may be given for mode_status depending on other factors.
Boolean EC_mode is stored in the time series output table to allow the user to
screen data for post-processing. For any outputs in which EC_mode = False,
the corresponding record should not be included in eddy covariance
calculations.
If the CPEC200 is not configured to use the valve module, there are only two
possible values for mode_status:
• Normal EC mode: This indicates the pump is on ( pump_ON = True)
• Standby mode (Pump is Off): This indicates the pump is off
( pump_ON = False)
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