Capture spectral not change immediately with changes of source level
Hi,
[Settings] sweepsa mode , output format [iq or both]
Step:
1. External SG source -10dBm@1GHz, Aaronia SA able capture spectral with the CW -10dBm @ 1GHz result in iq and both.
2(a) At this point change the SG level to -15dBm@1GHz, observed after 5x loop only manage to get back correct spectral with the CW -15dBm @ 1GHz result. First 5x loop still getting -10dBm. This happen "both" output format.
2(b)At this point change the SG level to -15dBm@1GHz, observed after 1x loop only manage to get back correct spectral with the CW -15dBm @ 1GHz result. First 1x loop still getting -10dBm. This happen "iq" output format.
**AARTSAAPI_ConsumePackets API able to help, not sure how it work. Can you help advice how to make it immediate get back correct spectral with the CW -15dBm @ 1GHz result.
Thanks in advance!
Best regards,
Ron95
You will have to provide more details on this. You're talking in terms of loop counts, but without any information how your loop is defined in terms of samples and time. Are we talking nanoseconds or milliseconds here? Ideally you could provide a working sample code that demonstrates the problem so we can reproduce it.
You can never assume to always get a truly immediate reaction, that is simply physically impossible. There are delays (even if they are often too small to even measure) in switching your signal generator power level, the signal transfer to the analyzer, the analyzer digitizing and processing the signal, the digitized data being sent out and received by the PC via USB and finally the data being processed by the receiving software.
Hi,
For 2(a), it take around 1ms - 2ms in each of the loop. I did for 200 loop.
For 2(b), it take around 7ms - 8ms in each of the loop. I did for 200 loop.
For the external source, the signal source is change from -10dBm to -15dBm, I have wait for 1 minutes, then only perform 2(a) and 2(b). I can sure that is not due to source level switching time.
I have try AARTSAAPI_ConsumePackets(10000000), it can reduce the 5x to 3. That mean if I ConsumePackets() by 1 million, at the third loop can get back correct spectral with the CW -15dBm @ 1GHz. Just that I not able to immediate get the level that I wanted. I feel the data are still inside, something to clear before new data can go in.
Here is the command being send.
Thanks in advance!
Best regards,
Ron95
What is your use case anyway?
Sweep mode is for measuring large frequency ranges and output spectra data. If you want to only measure a 3 MHz span and potentially want to get IQ data you likely want to use "raw" mode when opening the device (see the RawIQ and RawSpectrum example projects).
Either way, your snippet doesn't really demonstrate anything, except measuring the duration of one loop iteration (including initialization).
Thanks for the reply. Actually we are plan to using it in test automation in production. That scenario is needed in our use-case. Somehow have try with both raw mode, same observation.
Now I am using http server, did not have this observation.
One more question, I want control both SG and SA with http server, do have the http commands list to control it?
Please open a new thread since this is a new question.
