Campbell Scientific CR9000X Measurement and Control System - Manual (Page 361)

Section 9. Program Control Instructions
FieldCal (Function, MeasVar, Reps, MultVar, OffsetVar, Mode, KnownVar,
Index, Avg)
Used for setting up a zero, offset, or two point calibration function on a sensor.
The actual calibration operation is simplified through using the Calibration
Wizard included in CSI’s software packages. A program using this
instruction will normally require the instructions: LoadFieldCal,
NewFieldCal, and SampleFieldCal.
Syntax
FieldCal(Function, MeasureVar, Reps, MultiplierVariable, OffsetVariable,
Mode, KnownVariable, Index, Avg)
Remarks
When the FieldCal instruction is in a program, a Calibration file will be
created. The location (CPU or Card) of this file will be the same as the
running program that created it. The name of the calibration file will be the
same as the running program that created it, only it will have *.CAL for an
extension.
It is recommended that the Reps and Index parameters be non-
constant variables that are initialized to the desired values after
the BeginProgram instruction. This rule can be ignored if setting
up calibrations on single element variables, and the Mode
variable parameter for each FieldCal instruction in the program
is represented by a unique variable. NOTE
When writing a program for a Two Point calibration, the Reps parameter
for the FieldCal instruction should usually be initialized to 1, and the
MultiplierVariable and OffsetVariable variable arrays should be
dimensioned to the size of the MeasureVar variable array.
When writing a program for a Zero function, and it is desired to perform
the zero function on all elements of the array during a single scan then:
1. The Reps parameter value should be initialized to the size of the
MeasureVar variable array and the Index parameter value should be
initialized to 1.
2. OffSetVariable should be dimensioned to have the same number of
elements as the MeasureVar variable array.
When writing a program for an offset function, and it is desired to perform
the offset function on all elements of the array during a single scan then:
1. The Reps parameter value should be set to the number of elements in the
MeasureVar variable array, the Index parameter value should be set to 1
2. OffSetVariable should be dimensioned to have the same number of
elements as the MeasureVar variable array, and
3. KnownVariable should be dimensioned to have the same number of
elements as the MeasureVar variable array and be loaded with the offset
values for the elements of the MeasureVar array,
A Field Calibration function is started through changing the value of the
Mode parameter to 1. When performing a Zero or Offset function, this may be
all that is required (set the Mode to 1 while the sensor is undergoing the
desired zero or offset condition). The steps required for the different
calibration functions follow.
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