Campbell Scientific AP200 CO2/H2O Atmospheric Profile System - Manual (Page 71)

Appendix B. AP200 Diagnostics
The public variable diag_AP200 indicates conditions outside the normal
operating range for the AP200. Any value other than zero indicates a problem.
Diag_AP200 contains several error flags encoded as binary bits. To diagnose a
problem, first decode the value according to TABLE B-1 and then see the
corresponding section in this appendix.
TABLE B-1. Summary of Bit Numbers Indicating Conditions Outside Normal Operating Range
Binary Bit (LSB = 1) Numeric Value Error Condition
1 1 Battery voltage is too low
2 2 Valve temperature is outside its operating range
3 4 Pump temperature is outside its operating range
4 8 Pump pressure is not at the setpoint
5 16 Sample flow is outside its normal range
6 32 Cell temperature is outside its operating range
7 64 Cell pressure is not at the setpoint
Example 1:
Assume diag_AP200 = 34
Because 34 = 32 + 2, this indicates bit 6 (numeric value = 32) and bit 2
(numeric value = 2) are set. This means there are two problems:
• Bit 6: Cell temperature is outside its operating range
• Bit 2: Valve temperature is outside its operating range
This could arise if the system is powered up in cold weather, and the valve
manifold and IRGA sample cell have not yet reached their operating
temperatures.
Example 2:
Assume diag_AP200 = 16
This indicates bit 5 (numeric value = 16) is set. This means the sample flow is
outside its normal range of 100 to 300 ml/min.
Output Tables
Every sample of diag_AP200 is stored in the RawData output table.
However, only an average of diag_AP200 is stored in the output tables
IntAvg, CalAvg, and SiteAvg. The interpretation of this average, given as
diag_AP200_Avg, is slightly different than the original variable, diag_AP200,
for two reasons. First, it represents only the samples that are included in the
averages (see Appendix F, Valve Sequence Timing, for timing details).
B-1