M800 and E888/E816

[Scott@FP]

For the record Chris @ motec USA figured it out. What gets transmitted from the E888 is Hz * 10 in a range from -32768 to 32767, once 32767 is reached it wraps around to -32768. And since the sensor table values are limited from -32000 to 32000 we appear to be limited to 3200 Hz, not the 6KHz listed as the ECU can't understand the data above 32000 before it wraps back around to -32000 and sets a channel fault. Only idea I have is to try and set Diag Lo to -5 and Diag Hi to -6 and hope it wraps around w/o setting a fault, just a period of unstable measurement.

Probably not of interest to anyone except those trying to measure high shaft speeds such as turbos, blowers, or high speed shafts with multitooth hall effect sensors.

[RossB]

It sounds like Chris has answered your question. When you use an E888 digital input into an ECU you have to use a custom calibration and enter the values of frequency against speed.