03-21-2014 06:02 PM
HI
i have a a tachometer that conenected to motor shaft
the output of this tachometer is pulses and each 24 pulse give a 1 revoluation
i use labview FPGA to estimate the pulse frequency with LV VI that already provided by NI as shown in figure (1) the loop tested under 5MHZ
the problem is shown in figure (2) where during DC rotating the pulse frequency go to zero for then back again to normal.
this cause a problem in my speed control system.
best regards
03-21-2014 06:07 PM
debounce your input.
03-22-2014 05:27 AM
srm@viewpointusa.com wrote:
debounce your input.
Really !!! As I read before the bounces happened in switch ??
03-24-2014 08:54 AM
Hi mangood.
Probably, Stu is right. Here is a little document that might come in handy.
Rudimentary Circuit to Eliminate Glitches/Bounces on a Signal
http://digital.ni.com/public.nsf/allkb/93FA5F2325B220108625724500740A1D?OpenDocument
03-24-2014 12:57 PM
@FmTesla wrote:
Hi mangood.
Probably, Stu is right. Here is a little document that might come in handy.
Rudimentary Circuit to Eliminate Glitches/Bounces on a Signal
http://digital.ni.com/public.nsf/allkb/93FA5F2325B220108625724500740A1D?OpenDocument
i will try
03-24-2014 05:45 PM
I recommend a simple software debounce. it has been very effective in the past.
any equipment that vibrates and product spurious edges on a tach or encoder.
see attached. it is a modified version of one from NI set n= 5 0r 10 for your case and see how it works