L3Harris NARDA PMM ER8000 User Manual page 68

(Continued) Once the sweep is started, the ER8000 sends the value of each detector chosen in
the command. Each detector is made of a Little Endian 16 bit integer which
SSFD FreqStart; represents the value of that particularly tuned frequency. The value is expressed in
FreqStop; hundredth of dBm. Therefore, for each step, there will be a packet of n detectors (n
FreqStep; *2 bytes).
Detector; The order of detectors is fixed and is not related to the order issued in the command.
HoldTime; Rbw; For instance, PAQ is equivalent to QAP as well as RA is same as AR. The order of
MinAtt; Preamp; detector is as follows (from the first to the last):
Preselector;
ScanHoldT
Special meaning has the value NOLEVEL, -32700 (Hex 8044), which informs that
the detector has not been measured. This happens, for example, in Smart mode
where the alternative detector is taken only for those frequencies the Peak was
above the margin.
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 10 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 margin).
7-16 Remote control
1. Peak (which is always present)
2. QPeak (QuasiPeak)
3. RMS
4. AVG (Average)
5. C-RMS
6. C-AVG