Thanks all. Yes, I use a tachometer to measure the motor speed at the motor outboard cooling fan (this is the only place to measure the motor speed). Even if the machine RPM is put in as 1720 RPM (for example), this is never the true turning speed and the motor changes its speeds while collecting data. Using "fixed tach location", will the speed of the intermediate shaft be changed proportionally based on the ratio added to the reference RPM? As I'm using a tachometer, will the software auto calculate the speed of the intermediate shaft based on the ratio? Pseudo tach option is not needed with this fixed tach location?