Rockwell Automation 8520-GUM 9/Series CNC Grinder Operation and Programming Manual Documentation Set - Manual (Page 113)

Manual/MDI Operation Modes
Chapter 4
4-9
The control stops wheel motion during overtravel conditions. Overtravel
conditions can occur from 3 causes:
Overtravel Condition Cause
hardware overtravel The axes reach a travel limit, usually set by a limit switch or
sensor mounted on the axis.
Hardware overtravels are always active.
software overtravel Commands cause the grinding wheel to pass a software
travel limit.
Software overtravels are active only after the axis has been
homed, provided the feature has been activated in AMP by
your system installer.
programmable zone overtravel The axes reach a travel limit established by independent
programmable areas.
Programmable zones are activated through programming the
appropriate G--code.
We describe these 3 causes of overtravel in detail on pages 11-34 through
11-36.
When an overtravel condition occurs, all axis motion is forced to a stop.
The control is placed in cycle stop and one of these applicable error
messages appears.
If you get this error message: It means that:
“HARDWARE OVERTRAVEL (-) BY AXIS (X)” the specified axis has tripped either the + or -
hardware limit switch mounted on the machine.
“SOFTWARE OVERTRAVEL (+) BY AXIS (X)” an attempt was made by the specified axis to
enter the overtravel area defined by the
softlimits in either a positive or negative
direction.
“VIOLATION OF ZONE (2) BY AXIS (X)” an attempt was made by the specified axis to
enter the overtravel area defined by either
programmable zone 2 or 3.
When an overtravel of any type has taken place, you are not allowed to
feed the axis in the same direction as the feed causing the overtravel. Only
axis feed in the reverse direction is possible.
How a hardware overtravel condition is reset depends on the E-Stop circuit
design and the way PAL was programmed by your system installer.
To reset a software or programmable zone overtravel condition:
1. Determine whether the control is in E-Stop. If it is not, go to step 4.
2. Eliminate any other possible conditions that may have caused
emergency stop, then make sure that it is safe to reset the emergency
stop condition.
4.4
Resetting Overtravels