Campbell Scientific CR200/CR200X-series Dataloggers - Manual (Page 98)

Section 9. Programming
9.9.4 Expressions in Parameters
Read More! See Expressions (p. 87) for more information on expressions.
Many parameters allow the entry of expressions. If an expression is a
comparison, it will return -1 if the comparison is true and 0 if it is false ( Logical
Expressions (p. 88)). CRBASIC EXAMPLE. Use of Expressions in Parameters
(p. 86) shows an example of the use of expressions in parameters in the
DataTable instruction, where the trigger condition is entered as an expression.
Suppose the variable TC is a thermistor temperature:
CRBASIC EXAMPLE 13. Use of Expressions in Parameters
'DataTable (Name, TrigVar, Size)
DataTable (Temp, TC > 100, 5000)
When the trigger is "TC > 100", a TC temperature > 100 will set the trigger to
true and data is stored.
9.9.5 Arrays of Multipliers and Offsets
A single measurement instruction can measure a series of sensors and apply
individual calibration factors to each sensor as shown in CRBASIC EXAMPLE.
Use of Arrays as Multipliers and Offsets (p. 86). Storing calibration factors in
variable arrays, and placing the array variables in the multiplier and offset
parameters of the measurement instruction, makes this possible. The
measurement instruction uses repetitions to implement this feature by stepping
through the multiplier and offset arrays as it steps through the measurement
input channels. If the multiplier and offset are not arrays, the same multiplier
and offset are used for each repetition.
CRBASIC EXAMPLE 14. Use of Arrays as Multipliers and Offsets
Public Pressure(3), Mult(3), Offset(3)
DataTable (AvgPress,1,-1)
DataInterval (0,60,Min)
Average (3,Pressure(),IEEE4,0)
EndTable
BeginProg
'Calibration Factors:
Mult(1)=0.123 : Offset(1)=0.23
Mult(2)=0.115 : Offset(2)=0.234
Mult(3)=0.114 : Offset(3)=0.224
Scan (1,Sec)
'VoltSe instruction using array of multipliers and offsets:
VoltSe (Pressure(),3,1,Mult(),Offset())
CallTable AvgPress
NextScan
EndProg
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