Section 10. Troubleshooting
10.5.3 NAN and ±INF
NAN
(not-a-number) and
±INF
(infinite) are data words indicating an exceptional
occurrence in datalogger function or processing.
NAN
is a constant that can be
used in expressions as shown in the following code snip that sets a CRBasic
control feature (a flag) if the wind direction is
NAN
:
If
WindDir = NAN
Then
WDFlag = False
Else
WDFlag = True
EndIf
NAN can also be used in conjunction with the disable variable (
DisableVar
) in
output processing (data storage) instructions as shown in CRBasic example
Using
NAN to Filter Data
(p. 484).
10.5.3.1 Measurements and NAN
A
NAN
indicates an invalid measurement.
10.5.3.1.1 Voltage Measurements
The CR1000 has the following user-selectable voltage ranges: ±5000 mV, ±2500
mV, ±250 mV, and ±25 mV. Input signals that exceed these ranges result in an
over-range indicated by a
NAN
for the measured result. With auto range to
automatically select the best input range, a
NAN
indicates that either one or both
of the two measurements in the auto-range sequence over ranged. See the section
Calibration Errors
(p. 490).
A voltage input not connected to a sensor is floating and the resulting measured
voltage often remains near the voltage of the previous measurement. Floating
measurements tend to wander in time, and can mimic a valid measurement. The
C
(open input detect/common-mode null) range-code option is used to force a
NAN result for open (floating) inputs.
10.5.3.1.2 SDI-12 Measurements
NAN
is loaded into the first
SDI12Recorder()
variable under the following
conditions:
•
CR1000 is busy with terminal commands
•
When the command is an invalid command.
•
When the sensor aborts with CR LF and there is no data.
•
When
0
is returned for the number of values in response to the
M!
or
C!
command.
10.5.3.2 Floating-Point Math, NAN, and ±INF
Table
Math Expressions and CRBasic Results
(p. 483)
lists math expressions, their
CRBasic form, and IEEE floating point-math result loaded into variables declared
as FLOAT or STRING.
482
Summary of Contents for CR1000
Page 2: ......
Page 4: ......
Page 6: ......
Page 32: ......
Page 36: ......
Page 38: ......
Page 40: ......
Page 60: ...Section 4 System Quickstart Figure 16 PC200W View Line Graph 60 ...
Page 96: ......
Page 98: ...98 ...
Page 302: ......
Page 453: ...Section 8 Operation Figure 115 Using the Keyboard Display 453 ...
Page 456: ...Section 8 Operation Figure 118 Real Time Custom 456 ...
Page 457: ...Section 8 Operation 8 8 1 3 Final Memory Tables Figure 119 Final Memory Tables 457 ...
Page 458: ...Section 8 Operation 8 8 2 Run Stop Program Figure 120 Run Stop Program 458 ...
Page 460: ...Section 8 Operation Figure 122 File Edit 460 ...
Page 461: ...Section 8 Operation 8 8 4 PCCard Memory Card Display Figure 123 PCCard CF Card Display 461 ...
Page 478: ......
Page 506: ......
Page 536: ......
Page 636: ......
Page 642: ......
Page 644: ......
Page 676: ......
Page 677: ......