thinking of writing Agilent 2000x, 3000x sweep software, opinions? - Page 1
Forum section: electronics / projects

author: KTP
author_rank: Frequent Contributor
timestamp: August 10, 2012, 01:03:10 am
content: I want to start this in a new thread so as not to hijack the other one asking about uses of the AWG on the 3000x.I was thinking about having my wife write a small C# software program to add sweep functionality to the 2000x and 3000x scopes using the Agilent IO libraries. It wouldn't be strictly realtime, but maybe would have a nice little PC window interface that lets you set the start and stop sweep frequencies, type of sweep (lin, log, etc.) and channel(s) of the scope where you are measuring the waveform result. The program would then load each frequency into the function generator on the scope, capture the waveform, repeat for the next frequency, etc. It would then generate a Bode maginitude plot and phase plot on the PC, and possibly load these as a reference waveform on the scope also (not sure if that would be of use, but it should be possible).Really I would just want to implement the functionality of what you get in an LTspice simulation for real circuits in a very simple interface that even raw beginners could jump in and use. My wife can probably write this in about 4 hours, but if we get a few features nailed down I can probably convince her to spend a few days polishing it.I would provide this for free, but I am not going to go to the trouble of having her write it if this already exists or someone convinces me it won't work as I envision.So if you would like this software, respond to this thread and let me know please. If you can think of other cool things to add in...perhaps stuff dealing with the AWG on the 3000x, let me know that too.

author: djsb
author_rank: Super Contributor
timestamp: August 10, 2012, 07:13:10 pm
content: I'd be interested in the software. Also where can I find info on I/O the libraries used and the any documentation. Is any additional hardware needed for the Oscilloscope to be able to do this?Thanks.David.

author: KTP
author_rank: Frequent Contributor
timestamp: August 10, 2012, 07:21:01 pm
content: Quote from: djsb on August 10, 2012, 07:13:10 pmhey wow, cool...one other person is interested!heh, but seriously...you can get the documentation on the libraries here:http://www.home.agilent.com/agilent/redirector.jspx?action=ref&cname=AGILENT_EDITORIAL&ckey=2015162&lc=eng&cc=US&nfr=-33573.970756.00Or maybe this is the same thing in pdf:http://www.home.agilent.com/agilent/redirector.jspx?action=ref&cname=AGILENT_EDITORIAL&ckey=2015164&lc=eng&cc=US&nfr=-33573.970756.00

author: KTP
author_rank: Frequent Contributor
timestamp: August 14, 2012, 05:30:29 pm
content: Just a little update. I had some quick test code to check the speed of update of the AWG on a MSOX3024A and found it to be quite fast. I have now modified the code to generate a quite nice 1Khz to 1Mhz 2Vpp sine wave sweep of a RC low pass filter consisting of a 10Kohm resistor and a 100pF capacitor. This time I generated 120 frequencies from 1Khz to 1Mhz in a true log base 10 form (1000Hz, 1059Hz, 1122Hz, 1188Hz, ... ,891250Hz, 944060Hz, 1000000Hz)This resulted in the beautiful graph below (channel 1 is output from function generator into the 10K resistor in RC filter, channel 2 is voltage across cap in the RC filter):Edit: Note that this is not really want I intend to write, but just messing around. I intend to have the PC generate a high resolution Bode plot from measured data off the scope. I just wanted to see what a real time sweep might look like on the scope.

author: KTP
author_rank: Frequent Contributor
timestamp: August 14, 2012, 09:37:55 pm
content: Just a little more playing around. This time I wrote a linear sweep from 100Khz to 300khz with 250 points for a 2.5Vpp Sine wave into a LC filter. The values were 0.1uF for the cap and 10uH for the inductor. The sweep indicated resonance at about 166khz which is darn close to calculated values considering the parts are probably +/-10% or more.

author: djsb
author_rank: Super Contributor
timestamp: August 15, 2012, 08:10:45 pm
content: Can the AWG be made to do FM or AM modulation? If it can it would be very useful for receiver testing.Thanks.

author: tnt
author_rank: Regular Contributor
timestamp: August 16, 2012, 07:52:39 am
content: Not that I know of. And trying to 'emulate' this like for the sweep above would really not work.

author: KTP
author_rank: Frequent Contributor
timestamp: August 16, 2012, 04:27:17 pm
content: Quote from: djsb on August 15, 2012, 08:10:45 pmDo you mean programming the 8192 points of the AWG for a certain sine modulated sine? I just wrote a quick program to test that, with maybe ok results for some situations. For 8192 points on the modulated wave, the carrier wave will need to have fewer points defining it. I got pretty good results with 32 points for the carrier wave, meaning you can generate signals that are modulated by a frequency 256 times slower (ie, 256Khz modulated by 1Khz). It starts looking pretty decent at 64 points, but that obviously cuts you down to 128 times the modulation frequency for the carrier. Even 16 points might be acceptable though in some situations, so you could generate for example a 1Khz tone in the lower AM radio band.Here are some screenshots of various modulation and carrier frequencies, using the megazoom.edit: the first pic is mislabled...it is 128Khz modulated at 1Khz with 64 steps, not 128 steps

author: djsb
author_rank: Super Contributor
timestamp: September 23, 2012, 09:06:32 am
content: Hi,Any news on your progress. We haven't heard from you for a while!David.