> so I'd say > 2.5dinclockf=BPM > or > 2.5/dinclock period[sec]=BPM > 2500/dinclkper[ms] = BPM > does this make sense? Yeah, you are right... my derivation was similar, but I messed up the math along the way. I should have paid more attention before posting. Sorry for the confusion. :) -Dan G.