amp e MS3Pro ULTIMATE User Manual page 173

7.3 Ignition Settings
Setting to Falling Edge would result in an unstable signal - you'll see this as timing scatter and the RPM
bouncing around. And this is with a fairly clean signal, which the processor would see like this if triggering on the
correct edge:
If the wiring or sensor isn't perfect, and the signal becomes noisy, the CPU will see a signal like this instead:
There are several strategies the MS3Pro has to filter this out, which you enable from the Noise Filtering screen.
Use caution; an overly aggressive noise filter can easily cause the MS3Pro to filter out real pulses.
• Noise filter period - this sets a minimum pulse time to ignore, measured in clock cycles. Each clock cycle
is 0.02 microseconds, so a value of 4 corresponds to 0.08 microseconds. It can filter out very short noise
spikes, like this:
AMP EFI MS3ProUltimate manual version 1.203, firmware 1.5.0, 5/23/2017
7 ADDITIONAL ITEMS: BEYOND BASIC FUEL AND IGNITION CONTROL
Page 173