Rockwell Automation 8520 9/Series CNC Lathe User Manual
Page 208
Running a Program
Chapter 7
7-32
To perform a block retrace operation:
1.
Press the
<CYCLE STOP>
or activate the
<SINGLE BLOCK>
feature
button to stop program execution.
2.
Press the
<BLOCK RETRACE>
button.
After you press the
<BLOCK RETRACE>
button, the control retraces the block
that was being executed when the cycle stop occurred or retraces the block
just completed if you press the single block button, provided that the block
is a legal block for retrace.
While the block retrace function is active, the light in the
<BLOCK RETRACE>
button is on. The block that was shown as active when
the block retrace was activated still appears as the currently active block in
the program display area during the entire use of the block retrace function.
Important: If you use the
<CYCLE STOP>
button to halt execution to begin
a block retrace, the control re-executes the portion of the block that has
been executed. For example, if the block requests an axis move of 20 mm
and the axis has moved 12 mm when you press the
<CYCLE STOP>
button, a
block retrace reverses the axis direction 12 mm.
All retraced blocks are executed at the feedrate programmed for that block
though this may be modified by the use of the
<FEEDRATE OVERRIDE>
switch. See chapter 18.
Press the
<CYCLE START>
button at any time during a block retrace to
return the cutting tool to normal forward execution. Program execution
returns to the normal forward direction from the currently retraced block.
The control executes the retraced blocks in normal order until the tool is
positioned at the start point of block retrace. From this point it continues
program execution in a normal fashion unless
<SINGLE BLOCK>
is active.
If
<SINGLE BLOCK>
is active, the control halts execution when the return
from block retract is complete.
While block retrace is active, the control disables all jog features with the
exception of
<JOG RETRACT>
. See page 7-17. MDI is not available to
insert blocks during a block retrace operation.