mkj

Sweet!

Installed the beta update and updated the firmware - how do I get the extra channels etc? Also math C1-C2 is not working.

Thanks for the answer and I'll try that beta out - looks awesome! I needed a specific frequency so I created a math C1-C2 (modulation delta) and used to to get the zero crossing vs the demod C1 is waveform 1 carrier modulated (Va to AD598) C2 is waveform 2 carrier modulated - 180 out of phase with C1 (Vb to AD598) BLUE is C1-C2 PURPLE is demod from AD598 (Va-Vb)/(Va+Vb) showing the phase lag effect of filters on the response

So I tried this - but what do I set my trigger to? The math wave will always be at "0" time - the waveform channels will be the composite carrier and modulation so I cant trigger to that. How do I trigger to the waveform "modulation" part? I dont want to trigger to the "DEMOD" - if I do it will always be inphase to the math channel. I cant trigger on the initial waveform edge (carrier and mod) since the wave needs to be "on" for a few second for the demodulation to stabiilize.

Thanks - perfect. Didn't know you could do that equation w/o a channel input! Awesome.

Im trying to simulate an LVDT frequency response. So I have two amplitude modulated waveforms (analog discover waveform generator) with a 1000Hz carrier and low frequency modulation (1-30 Hz) to simulate the "movement" of the LVDT. These become my Va and Vb of an LVDT. I can feed the AD598 (LVDT asynchronous demod chip) with the waveforms and will get the demodulated (Va-VB)/(Va+Vb) ratio of the modulation. I need to compare phase lag at the modulated frequencies to evaluate phase shift caused by the AD598 filters. How can I get the modulated part of the Waveforms signal on the scope to be able to compare demod vs input phase? I tried a MATH channel: modulation = C1/(sin(2 pi fc) - Ac (C1 is waveform for Va, where fc and Ac are the carrier freq and amplitude) But this doesnt work... it seems not accurate enough to mix the equation with the actual data - getting spikes etc. Is there a way to just show the low freq modulation on a the scope? I have the AD original, and the AD3450 Ideally this would be a freq response sweep over 1-30 range of modulations, comparing the demod signal to the command modulate. But I can run this point by point if I can used the scope.

perfect - thank you how do you write the "phase" calculation equation?

Is there way to create a math channel or measurement for LVDT demodulation? The equation is based on the RMS voltage ratio: VRATIO = (VA_RMS - VB_RMS) / (VA_RMS + VB_RMS) I see you can create "measurements" with RMS, but can I use that in an equation somewhere for the ratio? Either as a "readout" or in the scope on a math channel? Similar question for resolver but that would get into whether the Va and Vb are in phase or not with the excitation. (Waveforms 3.18 AD3450 and AD Legacy)

I have a resolver I want to use with AD3450 - I can generate the excitation, and measure on the scope the VA and VB vs rotation Can I create a math channel or ? to calculate degRotation = ARCTAN( (Va*sin(theta)) / (Vb*cos(theta))) Were theta is phase shift comparted to excitation? I can do degRotation = ARCTAN(Va/Vb) but or course that doesn't give me quadrature (ie no phase) Are there ways to get phase?

Perfect! - thanks!

Why is the AD3450 specified for patterns as 16 x 16k? When I try to create a pattern - custom etc its only letting me have 8k samples. Win10pro, x64, Waveforms 3.18

Thanks - have been getting into using the waveforms sdk with python recently. This should help out quite a bit with streamlining my code. Documentation looks excellent as well! ?

Yes I've had this happen on the legacy AD, the demo (waveforms) and APP3450. All win10 x64 os.

to trigger on PC I use: FDwfDeviceTriggerPC(HDWF hdwf) - correct what do I set idxPin to ? in FDwfDeviceTriggerSet(HDWF hdwf, int idxPin, TRIGSRC trigsrc) Also -seems the online SDK trigger values are off? // trigger source typedef unsigned char TRIGSRC; const TRIGSRC trigsrcNone = 0; const TRIGSRC trigsrcPC = 1; const TRIGSRC trigsrcDetectorAnalogIn = 2; const TRIGSRC trigsrcDetectorDigitalIn = 3; const TRIGSRC trigsrcAnalogIn = 4;

I seem to have issues 3.17.1 waveforms crashing when using math channels. Add a few math channels - with simple scaling like -C1*130/5 Run the scope, and click on tabs for some of the tool: FFT, Hist, etc. Seems to crash regularly. Happens on demo, digilent(old), and ADP3450