3156B User Manual
Racal Instrument © 2005
Programming Reference 5-101
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_set(query)_FM_mod_freq
Description
Sets the frequency of the modulating waveform. The modulating waveform can be selected from 4 built-in
waveforms: Sine, Triangle, Square and Ramp. An arbitrary waveform can also frequency modulate the carrier
however, this waveform must be designed externally and downloaded to the arbitrary FM memory before it can
be used for modulating the carrier.
Channel Dependency: Common
C Syntax
ViStatus ri3156b_set_FM_mod_freq (ViSession instrHandle, ViReal64 FMmodulationFrequency)
ViStatus ri3156b_query_FM_mod_freq (ViSession instrHandle, ViReal64 * FMmodulationFrequency)
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.
FMmodulationFrequency
ViReal64
Programs the modulating waveform frequency.
Valid Range: 0.01 to 350e3
Default Value: 10e3
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.