Campbell Scientific CPEC200 Closed-Path Eddy-Covariance System - Manual (Page 89)

Appendix D. Control Bits
For diagnosing a problem using data saved in the output table, ts_data, the
state of fans and heaters is encoded into variable ControlBits to conserve
memory space. A user unfamiliar with converting a decimal number to binary
may find it convenient to use a decimal-to-binary converter that can be found
on the Internet. Alternately, follow the step-by-step troubleshooting
instructions as a guide through the conversion process.
Note: the CPEC200 controls power to the heaters and fans with a 16-channel
control module, the SDM-CD16S. This same module controls the valves and
the scrub pump, as noted in the table. The state of the valves and scrub module
are set by valve_number, and are not reported in ControlBits.
TABLE D-1. CPEC200 temperature control bits encoded in ControlBits
Binary Bit
(LSB = 1)
Numeric
Value
Corresponding
public variable
(bit is set if
variable=True)
Notes
14 - 16 Not used
13 4096 scrubFan_ON Scrub module fan is on
12 2048 scrubHeat_ON Scrub module heater is on
11 Used for scrub pump (not included in ControlBits)
10 512 pump_fan_ON Sample pump fan is on
9 256 pump_heat_ON Sample pump heater is on
8 128 valveFan_ON Valve module fan is on
7 64 valveHeat_ON Valve module heater is on
1 – 6 Used to switch valves (not included in ControlBits)
none 0 All heaters and fans are off
If ControlBits is greater than 4095, this indicates bit 13 of ControlBits is set.
This means the scrub module fan is on. To decode other temperature control
bits, subtract 4096 from ControlBits and compare the remainder to the bit
values below.
If ControlBits is greater than 2047, this indicates bit 12 of ControlBits is set.
This means the scrub module heater is on. To decode other temperature
control bits, subtract 2048 from ControlBits and compare the remainder to the
bit values below.
If ControlBits is greater than 511, this indicates bit 10 of ControlBits is set.
This means the sample pump fan is on. To decode other temperature control
bits, subtract 512 from ControlBits and compare the remainder to the bit
values below.
D-1