Rockwell Automation 8520 9/Series CNC Lathe User Manual

Page 376

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Axis Motion

Chapter 14

14-18

Important: When the control executes a G28 or G30 block, it temporarily

removes any tool offsets and cutter compensation during the axis move to

the intermediate point. The offsets and/or cutter compensation are

automatically re-activated during the first block containing axis motion

following the G28 or G30, unless that block is a G29 block. If a G29

follows, the offsets and/or cutter compensation remain deactivated on the

way to the intermediate point and are re-activated when the axis moves

from the intermediate point back to the point indicated in the G29 block.

The G04 command delays the execution of the next data block. Dwell
length is specified in either of two types.

Seconds
Number of spindle revolutions

The type used is normally dependant on the feedrate mode (G94 or G95)

active at the time. The type can also be permanently fixed to “seconds”

regardless of G94 or G95 mode, by setting the proper AMP parameter.

Dwell is not possible in the G93 inverse time feed mode.

In the G94 mode (feed per minute) G04 suspends execution of the
commands in the next block for a programmed length of time in seconds.

G94G04

P__;

X__;

U__;

Specify the required dwell time by either a P-, X-, or U-word in units of

seconds. It does not matter which of these three words you use, as long as

only one appears in the same block. The allowable dwell time is 0.001 -

99999.999 seconds.

When you program a dwell in seconds you system installer has the option

of writing PAL to allow a portion of the dwell to be skipped. If this feature

is used, when the appropriate signal is sent to PAL (from a switch or other

device) the control automatically skips any portion of the dwell that has

not been executed and proceeds to the next block in the program. The axes

positions when the skip signal is sent to PAL is recorded and stored as

system parameters #5071 - #5076. See specifics on the G31 skip cycles for

details.

14.3

Dwell (G04)

14.3.1

Dwell - Seconds

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