Teledyne LeCroy ArbStudio - Manual (Page 42)

ArbStudio
34 922244-00 Rev A

Read the voltage load on the multimeter

CF = Voltage Read at the load / Nominal voltage at the load. For
example if the value read is 4.9 V, CF=4.9 V/5 V = 0.98
Sampling Settings
This section of the General Tab allows for dividing sampling Base Frequency
(see Setup Sampling Rate Section) for both the signal carrier and for a
possible M-ASK modulating signal, respectively.
C
ARRIER
W
AVEFORM

Sampling Rate Prescaler (SRP) may assume values ranging from 1
(maximum frequency) up to 16777216 (minimum frequency), by
multiples of 2.

The optimal selection of SRP must take into account both the
maximum frequency of the signal to be generated and its duration.

The limit on the maximum frequency comes from the Nyquist
sampling theory which imposes a frequency generation at least two
times the maximum frequency of the signals generated.
For example, if a sinusoid must be generated at 10 MHz, its sample
frequency generation must be at least 20 Msps. In that case,
however, the sinusoid period is represented by only 2 points.
ArbStudio has a set signal duration limit for the memory depth used while
saving waveform samples. In fact, the memory space allocated to the
sample storage makes the waveform duration inversely proportional to the
generation frequency.
In particular, the maximum duration of a waveform is given by the number
of possible samples divided by the generation frequency.
For example, a maximum frequency of 250 Msps and a memory depth of
2,097,152 samples, done by setting SRP = 1 (sampling rate = 250 Msps), can
have saved waveforms with a total length of 8.388608 ms and a time
resolution of 4 ns.
However, by setting SRP = 20 (sampling rate = 12.5 Msps), the total
waveform length becomes 167.77216 ms with a time resolution of 80 ns.
M
ODULATING
W
AVEFORM
When M-ASK modulation is used you can set Mod Sampling Rate Prescaler
(MSRP) for the modulating signal independent of the carrier signal.