I had not pulled up the datasheet yet; I see that now. Turning the outputs of one or more accelerometers into the equivalent quadrature squarewaves is going to take some number crunching. I get the desire for something that is reverse compatible at the interface connector so it can just be plugged into the existing controller, but that makes for a lot of extra work.
ak
Jim bcp
Would it be better to change the code in the main control processor to accept the output from the accelerometer.