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CS110 Electric Field Meter
22
CallTable Tabslow
NextScan
EndProg
This program incorporates two different user-defined data tables,
Tabfast
and
Tabslow
.
Tabfast
contains 1 second measurements, while
Tabslow
contains 1
minute averaged data. Under certain error conditions the CS110 returns NAN
(Not-A-Number) for measured electric field rather than a questionable electric
field measurement. For example, the CS110 will detect if the shutter cannot be
properly closed at the completion of a measurement due to an obstruction. If the
shutter cannot properly close then the CS110 will return NAN for the electric field
measurement along with a status value indicating that the motor could not
properly close the shutter. The various CS110 status codes are described in
Appendix A.
The above program utilizes the array E_status(16) to store the various status codes
returned from a given measurement. The
Totalize
instruction in
Tabslow
computes the total number of occurrences for each array value during the output
interval. Consequently, the array E_status returns the total number of occurrences
of each status code during the associated 1 minute output interval. As given in
Appendix A, status codes 1, 2, and 3 are associated with good electric field
measurements, whereas each of the higher codes indicates a concerning condition
such as low-battery voltage or too much leakage current on the electrode
insulators.
There are times when it is desirable to exclude a measured result from an output
processing instruction such as
Average
. This can be conveniently accomplished
using a disable variable (
DisableVar
) associated with appropriate output
processing instructions. The last parameter of the
Average
instruction is the
DisableVar
and will exclude the current measured value when
DisableVar
is not
equal to zero. In order to prevent a single NAN electric field result from
corrupting measurements over the entire output interval, the variable meas_error is
used to disable writing NAN results to the
Average
(1,E_field,ieee4,meas_error)
instruction in
TabSlow
.
It is also sometimes desirable to keep a count of total measurement errors, which
is accomplished in the above program by the variable Error_Count. The last
stored value of Error_Count is retrieved from final storage at the beginning of the
program and Error_Count is incremented once during a scan each time status >6
from the
CS110
instruction. The Error_Count can be zeroed by means of
LoggerNet by accessing the Public variable Error_Count in the Numeric display
available in the Connect Screen.
Appendix F contains more example CS110 programs that users may find
beneficial in various applications. A more detailed description of CRBasic is
contained in the CR1000 Measurement and Control System Operator’s Manual.
8. CS110 Measurement Instructions
8.1 CR1000 Measurement Overview
The CR1000 datalogger can perform many different measurement tasks as defined
by measurement instructions in CRBasic. A brief explanation of CS110
measurement instructions is given followed by some specific examples. Further
measurement instructions and measurement details are provided in the CR1000
Measurement and Control System Operator’s Manual.