Rockwell Automation GMLC Reference Manual - Manual (Page 302)

Publication GMLC-5.2 - November 1999
Auto Correction (Configure Cam) 265
When a good registration event occurs on the registering axis, the
PCAM_good_registration_count variable for the axis is incremented. The
previous registration position is subtracted from the registration position
of the registering axis to determine the distance between this registration
event and the last in the position units of the registering axis. The nominal
length is then subtracted from this registration distance to determine the
registration error. This calculated registration error is then unwound to ±
1 /
2
the nominal length and accumulated. Finally, the registration error in the
position units of the registering axis is converted to the registration error
in the position units of the master axis by multiplying it by the ratio of the
master axis cycle to the registration axis cycle as shown below.
The calculated registration error in the position units of the master axis is
then used to phase shift the slave axis via a dedicated auto-correction
indexer to correct for error trends in the registration distance as shown
earlier for relative auto-correction.
See Phase Shift Moves in the Move Axis section of this chapter for more
information on phase shift moves. See Relative Auto-Correction in this
section for more information on the operation of relative ratioed auto-
correction.
Re . [ ] Re . [Re . ]
Re
g Error Master Axis g Error g Axis
Master Cycle
gistering Cycle
= ×
!
ATTENTION: Be sure to enter the master axis cycle
and registration axis cycle values in feedback counts,
not position units.