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Tacho Output on MSExtra 2
AntonUK - 23/6/15 at 08:55 PM

Hi All.
I'm running a megasquirt v2 on a v3 board with the MS extra firmware.

I've just hooked up IAC1A to the rev counter and set the relevant output on tuner studio. I cannot run the engine atm, is there a way to test the output without the engine?

I've tried the coil test mode but nothing happens with the tacho, not sure if it should?

Anyone tried it?


dave_424 - 23/6/15 at 09:01 PM

Not tried to test it, but that's the exact setup I use to drive my ZX9 clocks, works a treat


ali2992 - 24/6/15 at 04:31 PM

I have same problem, I'm not sure if this is how you do it but if you go on "can/bus test mode" or something like that, at the top right of tuner studio you can then test/pulse the tacho output. However I'm only assuming here, all I've noticed when doing it for mine is an increase in the voltage output for my tacho output. I'd be expecting the voltage to pulsing on the multimeter to simulate engine revving? Or is it too fast for the multimeter?


dave_424 - 24/6/15 at 07:00 PM

From what I've read, when a multimeter reads fast pulses it interpretes it as a voltage. E. G. 12v pulsed at a fast 50% duty cycle can be seen as 6 volts


ali2992 - 24/6/15 at 07:04 PM

Ah, thank you! That makes sense now with my readings


AntonUK - 28/6/15 at 05:41 PM

Thanks All, Didn't find the CAN options but will have another look.

In the end I just got on with getting the engine running and tested it properly. Works perfect