How do I display 'NaN' (missed pulses) from Analog Tacho Processing as zero spee

[AEI_JR]

I have an application that reads speed pulses from a previously recorded TDMS file, then converts the pulses to a speed profile using 'Analog Tacho Processing' (ATP) from the S&V library.  The TDMS files measure a motor running up and down, with time in between where the motor is not rotating.  When ATP does not sense a pulse, it is simply ignoring that data, rather than inserting zero values, which means I can't line up the time axis of the speed profile with my other data.  Is there a way to force ATP to output zero values when pulses are not present?

[Online_Courses]

Hi AEI_JR-

     Here are a couple of things to try:

1.  Use the OAT Tacho Process.vi.  This is on the functions palette»Sound and Vibration»Tachometer Processing.  It has an input called "missing pulses?".  It says that if you wire a true constant to this VI, it will find the missing pulses and interpolate them.  You might experiment with this to see if it will give you what you want.

2.  There are a couple of outputs from the Analog Tacho Processing Express VI called "no speed detected" and "current speed".  You may be able to use these outputs in conjunction with your speed profile to determine the missing values and then insert a zero into your data.  You can index through every value that comes out of the speed profile output, see if the "no speed detected" or "current speed" outputs indicate NaN, and replace that NaN with a zero as you build a new speed profile.

     I hope this helps.  Best of luck with your application!

[AEI_JR]

Thanks for the reply.  I ended up breaking the data into shorter waveforms and running it through a for loop.  I then check to see if 'current speed' output from the analog tach vi is not a number: if so, I replace it with a zero value.  Pretty inelegant, and it's slow, but it does the job.

Kudos for the assist!