7.2 G
ENERAL
P
ROGRAMMING
D
IRECTIONS
IN
L
AB
V
IEW
Switch into the diagram view of the vi-files. The parameters are set and read with
the DLL functions or double click into this functions to open the window, which
allows to correlate the function with a DLL-function and its exchange value:
The used library is the 'lockin.dll'. The example sets the frequency with the function
'SetLockInFreq'. The value is of numerical type and 8-Byte Double long.
Needed data types in the DLL and their equivalent in LabView are:
•
double
numerical type, 8-Byte-Double
•
integer numerical type, signed 32-Bit-Integer
•
longint
numerical type, signed 32-Bit-Integer
•
PInteger
numerical type, signed 32-Bit-Integer (Pointer to value)
•
PDArray
array type, 8-Byte-Double (1 dimension, array pointer)
•
longbool
numerical type, signed 32-Bit-Integer
•
PChar
string type, pointer to C-String
The frequency sweep example, for instance, consists of a loop, in which each single frequency
value in the spectrum is calculated based on the input parameters 'Start Frequency', 'Stop
Frequency' and 'Number of Steps', while the results are stored and displayed in a graphical
window. It includes the sub-vi's 'Input_Lockin' and 'GetTimeConstantValue.vi'. They only connect
the numerical data and DLL function.
Manual Anfatec PCI-Lockin Amplifier AMU2.4 – Rev. 1.10 dated 30/09/20
Page 39 (70)
