You are likely to see two kinds of encoders: TTL and differential (rs422). TTL means there's a single wire for the each signal (e.g. "A"), and it roughly follows TTL voltage level for high and low signals.
differential means there are two wires for each signal (e.g., "A+" and "A-"). The logic-level value is determined by looking at the difference in voltage between A+ and A-, and this gives increased immunity to certain kinds of noise. http://en.wikipedia.org/wiki/Differential_signaling Differential signals are intended to be decoded into a logic-level signal with a chip called a differential receiver such as the ones in this family: http://www.national.com/mpf/DS/DS26LS33M.html If you scope one phase and it looks like a clean, logic-level signal then it is sure possible to use it and ignore the complimentary signal. Jeff ------------------------------------------------------------------------- This SF.Net email is sponsored by the Moblin Your Move Developer's challenge Build the coolest Linux based applications with Moblin SDK & win great prizes Grand prize is a trip for two to an Open Source event anywhere in the world http://moblin-contest.org/redirect.php?banner_id=100&url=/ _______________________________________________ Emc-users mailing list Emc-users@lists.sourceforge.net https://lists.sourceforge.net/lists/listinfo/emc-users
