REW Beta Release REW API beta releases

[John Mulcahy]

Builds updated today (beta 54) with the following change:

• Fixed: Null pointer exception could occur when saving RTA data with harmonic phase display selected

 

[yys310]

Is there a way to measure driver current distortion by REW?

 

[John Mulcahy]

Is there a way to measure driver current distortion by REW?

I guess you could make a sweep or stepped sine measurement across a small resistor in series with the driver, on the ground side if your interface input is single-ended.

 

[sm52]

...if you have a means of generating an inverted copy of the input signal and applying it to a second input channel the cross-correlation processing with the Invert correlation reference option may allow common mode noise on the inputs to be cancelled. There is a thread on cross-correlation processing here.

I tried this option. When one input is used, the harmonics are no higher than 3%, when the second input is fed an inverted version of the first input, the harmonic levels are almost the same as the main signal. Maybe I should do something else?

 

[John Mulcahy]

Sounds like the way the inverted signal is being generated is causing some issues. Probably worth asking on the thread I linked.

 

[sm52]

Sounds like the way the inverted signal is being generated is causing some issues. Probably worth asking on the thread I linked.

Thank you. I will try. Another question. Is there a way to make a full copy of a measurement after uploading it to REW? I know of several ways to get a copy, but they all lose the left impuls window, so the distortion is no longer shown.

 

[sm52]

John Mulcahy,​

in that DAC-ADC testing thread are we talking about a loop connection? And that's all? From output loop to input1. And if you add inversion, then from output to input1 and inversion to input2. So?

 

[sm52]

If REW can handle two inputs, can it use calibration files separate for each input at the same time?

 

[serko70]

Alignment tool API very rarely throws an irrelevant error message:

The above error was caused during an impulse alignment @ 20Hz. Details below:

If of any relevance, the same error was also here:

Beta 54

 

[John Mulcahy]

If REW can handle two inputs, can it use calibration files separate for each input at the same time?

Yes.

 

[John Mulcahy]

Is there a way to make a full copy of a measurement after uploading it to REW? I know of several ways to get a copy, but they all lose the left impuls window, so the distortion is no longer shown.

Windows are not affected, but response copy does not include distortion data. If you want an identical copy of a measurement just save it and reload it.

 

[John Mulcahy]

in that DAC-ADC testing thread are we talking about a loop connection? And that's all? From output loop to input1. And if you add inversion, then from output to input1 and inversion to input2. So?

I don't really understand the question, but if you have questions about that ASR thread then ask them there.

 

[John Mulcahy]

Alignment tool API very rarely throws an irrelevant error message:

The error buffer might be full with previous errors. I'll add some code to only keep the most recent errors.

 

[sm52]

John Mulcahy,​

thanks for the answers.