My scope tacho trace looks like this from the previous post....
Using the simulator board as a plug in to generate RPM and using Tunerstudio as the monitor.
Looking with a scope at 1,000 rpm the square wave has a frequency of around 1.6-1.7 milliseconds (it jitters a bit)
At 10,000 rpm it is around 170 micro seconds (0.17 ms).
so at 1000 rpm (ref PSIG), I should see 50hz or 20ms as a duty cycle on the tacho pulse but I am seeing around 10 times less than that (1.6-1.7ms)?
Looking at one ignition out put the duty cycle is 6ms (166.6 hz) at 10,000 rpm and around 63ms (15.8hz) at 1000 rpm
so it looks like my fire frequency is 3 x faster than what it should be (@10k rpm, duty is 6ms/166hz) .
from PSIG I should be seeing 10,000/60*3 = 500hz which is a duty of 2ms
Have I done something wrong with my configuration (previous post) from an expected 3 events per revolution across the 3 cylinders?
I think I created a bit of confusion (in my own head at least). Ignoring tacho for now....
@10k RPM I am measuring a duty cycle on ignition output 1 of 6ms which is 166.6 hz, which is correct (10,000/60 = 166.6hz). SO all good on ignition.
The Tacho pulse however covers every ignition event so is 3 times faster (all 3 ignition outputs fire in 1 revolution). So my tacho should be at 500hz@10k RPM. 500hz is 2ms.
My tacho pulse @10k is closer to 2 micro seconds (10x faster), so I can only assume it is a function of the number of cylinders (6)I am having to kid Speedy to use to get my 3 ignition and injector outputs? But the maths doesn't quite tie up??