14-22 Remote control
(Continued)
SSFD
FreqStart;
FreqStop;
FreqStep;
Detector;
HoldTime;
Rbw;
MinAtt;
Preamp;
Preselector;
ScanHoldT
FFT will be used, as opposed to standard sweep step by step, when the following
conditions are matched:
o Detector is either
o Peak (only) and HoldTime < 50ms or
o SMART and an alternate detector.
o Stop frequency <= 150kHz
o Span (Stop frequency - Start frequency) >= 5 kHz
o Step frequency = 50Hz
o RBW = 200Hz
After having terminated all steps and sent all data, the string
SFD_END<RC><LF> is then sent informing the user there are no more data left.
Any started sweep can be stopped by sending the command ASBK which
abruptly terminates it.
In case the sweep was prematurely terminated by the command ASBK, the end
of sweep (which will not contain all expected data) is SBK=OK<RC><LF>
Here is an example of the command:
#SSFD 1e6;10e6;10e3;PAR;0;6;10;OFF;ON*
Which triggers a sweep from 1 MHz to 10 MHz using a step of 5 kHz. Detectors
are Peak, AVG and RMS. The hold time will be the minimum suitable
(automatically adjusted by the unit). RBW is 9kHz. MinAtt is 10 dB which means
that the attenuator will not switch below 10 dB attenuation. Preamplifier is OFF
while the Preselector is turned on.
Here, for each step there will be a packet of 3 detectors per step (Peak, AVG and
RMS in this order) counting thus 6 bytes (3 * 2) per step.
Here is another example:
#SSFD 9e3;150e3;50;SPQ;1000;7;10;OFF;ON;100*
Which triggers a sweep from 9kHz to 150kHz using a step of 50 Hz. Detector is
Smart QuasiPeak using a hold time of 1s in re-measuring those frequencies
which value was over the limit scanned using 100ms holdtime . RBW is 200Hz.
MinAtt is 10 dB which means that the attenuator will not switch below 10 dB
attenuation. Preamplifier is OFF while the Preselector is turned on.
In this case, as all the needed conditions are matched , FFT is used to perform
the Peak scan.
Here, for each step there will be a packet of 2 detectors per step (Peak and
QuasiPeak in this order) counting thus 4 bytes (2 * 2) per step. Of course, most of
QuasiPeak value will be populated by NOLEVEL as QuasiPeak will be
measured only for few frequencies (the ones which value is above the limit).
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