3156B User Manual
Racal Instrument © 2005
Programming Reference 5-167
Return Values
Displays the return status of the function call. If the function was successful, it will return a status of
VI_SUCCESS, otherwise it will return an error code. Passing the error code into the function
"ri3156B_error_message()" will return a string describing the error.
Ri3156b_load_FSK_data_file
Description
This function is similar to the ri3156b_load_FSK_data function except it points to a file name that was already
prepared and stored on your computer. The complete path to the file location is required. This function loads
the data stream that will cause the 3156B to hop from carrier to shifted frequency and visa versa. Data format is
a string of "0" and "1" which define when the output generates carrier frequency and when it shifts frequency to
the FSK value. "0" defines carrier frequency,"1" defines shifted frequency. Note that if you intend to program
marker position, you must do it before you load the FSK data list.
Below you can see how an FSK data table is constructed. The sample below shows a list of 10 shifts. The
3156B will step through this list, outputting either carrier or shifted frequencies, depending on the data list: Zero
will generate carrier frequency and One will generate shifted frequency. Note that the waveform is always
sinewave and that the last cycle is always completed.
Channel Dependency: Independent
Sample FSK Data File
0 1 1 1 0 1 0 0 0 1
C Syntax
ViStatus ri3156b_load_FSK_data_file (ViSession instrHandle, ViString FSKFileName, ViInt16
FSK_word_length)
Parameters
Name
Variable
Type
Description
instrHandle
ViSession
The Instrument Handle is used to identify the unique
session or communication channel between the driver
and the instrument. If more than one instrument of the
model type is used, this will be used to differentiate
between them. Note that the initialize function may be
used to associate multiple instrument handles with a
single instrument.
FSKFileName
ViString
Points to a file name already stored in your computer’s
memory. Full path is required. File extension is *.fsk
Valid Range: 0 or 1
