User Manual – Rev AJ
California Instruments
Figure 4-34: Waveform Crest Factor Affects Max. rms Voltage
The figure shown here illustrates the relationship between the crest factor of the wave sh
its “peakine
ape (or
ss”) and the maximum peak voltage allowed for a given voltage range. Since the
e programmable rms voltage has to
y
orm on the left. The sine wave on
the right can be programmed to the full 300 V rms as this still falls within the same peak voltage
Restrictions
peak voltage cannot exceed the AC source’s capabilities, th
be restricted, in this case to onl 167.8785 volt for the wavef
limitation of the AC source.
If the MX Series is used over the bus, the “:VOLT? MAX” query command can be used to
determine the maximum allowable RMS voltage for the selected waveform. Using the returned
value as part of a program will prevent range errors.
4.4.6 Frequency Response
The user may create a waveform that contains any number of harmonic frequencies of the
fundamental. The AC Source itself however has a finite signal bandwidth and will attenuate
higher frequency components of the signal. To limit the maximum frequency component of the
output signal, the 3Pi controller automatically applies a band-pass filter to all custom waveforms
as they are downloaded. The controller implements the following process for user defined
n or equal the
= Fmax/(level * h )
m
and the label will be deleted from the waveform catalogue.
h
determine the maximum allowable fundamental frequency for the selected waveform. Using the
Lim
belo
Wa
n error
Tra
entry will not check for the error until transient execution.
waveforms:
Each down loaded waveform will have a computed frequency limit that is less tha
maximum frequency limit of the AC source. The frequency limit is a function of the harmonics
content of the waveform and will follow the equation below.
Fmax
h
n
If F axh is below the minimum frequency limit, the waveform will be rejected at down load time
If t e MX Series is used over the bus, the “:FREQ? MAX” query command can be used to
returned value as part of a program will prevent range errors.
its assume a program of full-scale voltage. No adjustments for voltage setting are made
w the full-scale value.
veform selection and frequency programming will be subject to the above limit. A
message will be generated to reflect this type of error:
"22,Waveform harmonics limit"
nsient editing will also generate the above error during keyboard entry. Remote transient
124 MX
Series