• State
  • Locked Locked
  • Replies 3 replies
  • Subscribers 79 subscribers
  • Views 526 views
  • Users 0 members are here
Support feedback
Options
Options
Related

This thread has been locked.

If you have a related question, please click the "Ask a related question" button in the top right corner. The newly created question will be automatically linked to this question.

EVM430-FR6047: Jumping dTOF

Matthias Luzius
Prodigy 60 points

Part Number: EVM430-FR6047

Hello to all,

I have problems to capture the correct paek point from the ADC-captured points to calculate the abs. and delta TOF. The theshold/calculated peak is jumping + or - 1µs (one pulse earlier or later at 1MHz). You can find the parameters and an example of the waveforms below.

Conditions:

Water metering at zero-flow. As you can see the DNS Signal is jumping from 209.6 to 210.6, which is the correct point.

After a while the UPS or DNS Signal jumps again.. Therfore I changed the params "Envelope Crossing Threshold" and "Search Range", but it is all the time the same problem.

Some outliers would be ok, but at the moment its not possible to measure a reliable signal.

What other parameters could I change, in order to improve it?

Thanks for your help.

Regards,

Matthias

  • 0
    TI__Mastermind 47425 points

    Hello Matthias,

    Can you please provide the ADC capture?  It could be an issue with the envelope crossing threshold, but I would need to see the ADC signal.

  • 0 in reply to Eddie LaCost
    Prodigy 60 points

    Hi Eddie,

    you can see the adc capture at zero flow. I´m sure with the correct Parameters the DC Offset schuld not be a big problem... Maybe the windowing-mode is an option?

    Regards

    Matthias

  • 0 in reply to Matthias Luzius
    TI__Mastermind 47425 points

    Matthias,

    The offset is very large and the signal does not look very good with UPS and DNS not being very well aligned.  We should address cleaning up this signal first. 

    What type of pipe are you using?  Is this a clamp on or invasive configuration of the transducers? 

    I noticed that your gap between pulse start and ADC capture is quite long.  Is there a very large gap between the transducers?  I am wondering if the signal in the ADC window is actually a further reflection of the signal.

**Attention** This is a public forum