Rockwell Automation GMLC Reference Manual - Manual (Page 294)

Publication GMLC-5.2 - November 1999
Auto Correction (Configure Cam) 257
• the PCAM_registration_error variable displays the current
registration error value
• the PCAM_average_registration_error variable displays the average
registration error over the last ten registrations
• the PCAM_auto_correction_to_go variable displays the current
remaining distance to go of the auto-correction indexer
• the PCAM_good_registration_count variable displays the current
number of good registration events
• the PCAM_bad_registration_count variable displays the current
number of consecutive out-of-tolerance registration events
• the PCAM_missing_registration_count variable for the slave axis
displays the current number of consecutive missed registration counts
See the System Variables chapter of this manual for more information on
these variables.
Absolute (Target) Position
Enter a value or expression equal to the expected or desired absolute
position of the registration event on the registering axis in the position
units of the Master Axis in the Absolute Position field. This is the value
that is subtracted from the measured registration position whenever a
good registration event occurs to determine the phase shift correction for
the slave axis.
Tolerance
A tolerance is a range on either side of the registration (target) position.
Setting a tolerance limits error correction to only those errors that fall
within this range, and prevents the motion controller from trying to
correct unusually large errors. Large errors mean that serious problems
exist, either with the hardware or the software running it. These large
errors go well beyond mere axis slippage, or inconsistent material errors
that auto-correction can remedy.