Operation Theory 77tion and current motion command’s target position in order tocalculate relative pulses of current command then send resultsinto pre-register. Please check if the target position is the samewith current command position before continuous motion. Espe-cially after the home function and stop function.4.6 ComparatersThere are 5 counter comparators of each axis. Each comparaterhas dedicated functions. They are:1. Positive soft end-limit comparator to command counter2. Negative soft end-limit comparator to command counter3. Command and feedback error counter comparator4. General comparator for all counters5. Trigger comparator for all command and feedback coun-ters4.6.1 Soft End-Limit ComparatorsThere are two comparators for end-limit function of each axis. Wecall them for the soft end-limit comparators. One is for plus or pos-itive end-limit and the other is for minus or negative end-limit. Theend-limit is to prevent machine crash when over traveling. We canuse the soft limit instead of a real end-limit switch. Notice thatthese two comparators only compare the command position coun-ter. Once the command position is over the limited set inside thepositive or negative comparators, it will stop moving as it touchesthe end-limit switch.4.6.2 Command and Feedback Error Counter Compara-torsThis comparator is only for command and feedback counter error.Users can use this comparator to check if the error is too big. Itcan be set a action when this condition is met. The actions includegenerating interrupt, immediately stop, and deceleration to stop.
