On Sun, 13 Feb 2011 16:52 -0700, "YES NOPE9" wrote: > I can find no mention of the voltage range for "zero" and "one" values to > the control input. I also see no mention of the impedance the control > input presents. Is a zero =3D=3D> zero to 2.4 volts ? Is a one =3D=3D> = 2.4 > volts to 4.8 volts ? Is there hysteresis ? In my limited experience I would say there is hysteresis.=20 The logic high voltage does not vary with supply and is based on the internal voltage regulator of the servo chip, which is somewhere around 3 volts. Cheers, Bob --=20 http://www.fastmail.fm - Email service worth paying for. Try it for free --=20 http://www.piclist.com PIC/SX FAQ & list archive View/change your membership options at http://mailman.mit.edu/mailman/listinfo/piclist .