Rockwell Automation 8520 9/Series CNC Lathe - Manual (Page 341)

Chapter 12
Overtravels and Programmable Zones
12-13
Tool motion stops during overtravel conditions that occur from 3 causes:
Cause: Description:
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 axis 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 the system installer.
Programmable zone
overtravel
The tool reached a travel limit established by independent
programmable areas. Programmable Zones are activated through
programming the appropriate G-code.
In all cases, the control issues an error message.When an overtravel
condition occurs, all axis motion stops, the control goes into cycle stop and
one of the these error messages appears.
Error Message: Description:
HARDWARE OVERTRAVEL
(-) BY AXIS (X)
indicates that the specified axis has tripped either the + or -
hardware limit switch mounted on the machine.
SOFTWARE OVERTRAVEL
(+) BY AXIS (X)
indicates that the specified axis has entered the overtravel
area defined by the software overtravel limits in either a
positive or negative direction.
VIOLATION OF ZONE (2) BY
AXIS (X)
indicates that a tool has reached the specified axis overtravel
area defined by either programmable zone 2 or 3.
When an overtravel of any type occurs, axes cannot move in the same
direction as the feed causing the overtravel. Only axis motion 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 an
emergency stop, then make sure that it is safe to reset the emergency
stop condition.
3. Press the
<E-STOP RESET>
button to reset the emergency stop
condition. If the E-Stop does not reset, it is a result of some cause
other than overtravel.
4. Make sure it is safe to move the axis away from the overtravel limit.
5. Use any of the jog features described on page 4-1 except homing, to
manually move the axis away from the limit.
END OF CHAPTER
12.5
Resetting Overtravels