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HELP! Dynon RPM

n38139

Well Known Member
I just installed a Dynon Skyview system in my airplane with a new SV-EMS220 and I cannot get the Tach to read correctly. I had a D180 in it before had one resistor in the line and the RPM was correct. I am now up to 3 in my SV and it bounces all over the place and when it gets close to reading correctly, it is still 1000 or so above idle. The guy at Dynon told me just to add resistors. Anybody have the same problem or insight how to fix this?

thx
 
Need to know where you are getting your tach reading. Magneto? P-Mag? Other?

If magneto, are you pulling from the p-lead?

Have you confirmed the PPR is set to 2 (assuming 4 cylinder).
 
EMS Tach Input

Do you know which pin the tach input is connected to? I am wondering if it isn't connected to the low voltage pins rather that the standard inputs. Standard inputs for magneto's is pin 32 and 33
 
Dynon Help

I have standard Slick Magnetos, 4371 and 4370 and both leads go to pins 32 and 33. When I talked to Dynon, he couldn't find anywhere to tell the SV what the number of pulses were / are. I didn't find it either but I may have missed the text.
 
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what size resistor? how are you installing multiple resistors (serial or parallel). Usually you keep upping the size of the resistor until it works reliably. multiple resistors can be problematic if you don't understand how that impacts things.

The high reading could be an improper setting for number of pulses. This is often misunderstood. 4 cyl mags are usually 2 pulses per rev.

Larry
 
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RPM setup value

I have standard Slick Magnetos, 4371 and 4370 and both leads go to pins 32 and 33. When I talked to Dynon, he couldn't find anywhere to tell it the SV what the number of pulses were / are. I didn't find it either but I may have missed the text.

Tachometer pulses/revolution are set in the Engine Information Wizard – SETUP MENU > HARDWARE CALIBRATION > EMS CALIBRATION > TACHOMETER CALIBRATION.

Normally a 4 cylinder is set to 1, and a 6 cylinder is set to 1.5.

Brian
 
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That maybe the problem, the guy at Dynon didn't seem to be aware of how to do it. Like I said in my original post it worked great on my D180 with only one resistor.

I will check it in the morning.

Thanks
 
Tach Setting

Steve,
You can always ask for me when you call. I am still training the other two guys. It is a slow process.
 
i set the value in the Engine Information Wizard (SETUP MENU > HARDWARE CALIBRATION > EMS CALIBRATION > TACHOMETER CALIBRATION) to 1 but still get an RPM reading twice as much as it actual is. I do have steam RPM gauge that indicates correctly.

I got the Signal from the P-Mag and i am sure that the correct Pin# was defined in the Setup menu.

any ideas?
 
Look at page 6 of the pMag installation manual. The four cylinder pMag puts out two pulses per revolution.

For pMags, no inline resistor is used.

Carl
 
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