Rockwell Automation GMLC Reference Manual - Manual (Page 529)

Publication GMLC-5.2 - November 1999
492 Motion Variables
PCAM_good_registration_count is incremented when an in-tolerance
registration event occurs. As shown above, the first registration event that
occurs within the specified tolerance is considered the good registration.
All registration events that occur after a good registration event, and
before the beginning of the next tolerance area, are considered bad—even
if they occur within the current tolerance. If you did not select Tolerance
in the Configure CAM block’s Auto Correction page, all registration
events on the specified axis are considered good.
PCAM Missing Registration Count
PCAM_missing_registration_count is the current number of
consecutively missed registration events that have occurred on the
registering axis for a position-lock cam with Auto-Correction enabled.
In the Tag Explorer select both Axis System Variables and the desired
axis, then select PCAM_missing_registration_count in the Tag Window.
A registration event is deemed to be missing if either of the following is
true:
• the position-lock cam master axis (relative and absolute)
• the registering axis (relative ratioed and absolute ratioed)
moves one of the following:
• a distance equal to the specified nominal length plus the specified
tolerance past the last in-tolerance registration event (relative and
relative ratioed)
• past the position specified by the absolute target position plus the
specified tolerance (absolute and absolute ratioed) without the
occurrence of another registration event
The following illustration demonstrates missing registration for relative
auto-correction.