Sub-pulses in LabVIEW FPGA

[ashvin0703]

The pulse per rev is obtained from a fibre optic and a disc attached to the shaft. Digital pulse (+5V max).

[xseadog]

Oh

I am confused now you are saying pulse per revolution. Which would mean an index pulse!

A pulse can be described as a sharp transistion from one state to another. ( Refering to electronic world)

Utilising a digital pulse would suggest it is either on or off!

So atttempting to measure  100 sub pulses would be meaning less if you intend to every 3.6 degrees!

xseadog

[ashvin0703]

thanks

[gsussman · Accepted solution]

I believe your best bet would be to oversample the signal as stated before. How much oversampling really depends on what else you have to do on your FPGA that takes up space. I would oversample as much as possible.

Use the index pulse to segment your data stream from one index pulse to the next. At that point you have 1 rev worth of data. Pick the points that correspond to the 3.6 degree increments (you can decide wether you want to use the nearest sample or interpolate between samples)

This should give you the cleanest solution, and easily account for the speed variation of the shaft.

[ashvin0703]

First, thank you to you all for your help and suggestion. As suggested by stu and gsussman, oversampling is so far the better way to deal with my problem. Thank you again