4 g-codes (preparatory functions) – Rockwell Automation 8520 9/Series CNC Lathe User Manual
Page 290
Introduction to Programming
Chapter 10
10-22
Feedrates are expressed by the distance of movement per interval.
Depending on the mode of the control and the results you want, the
distance can be millimeters, inches, meters, or revolutions. The interval
can be minutes or revolutions.
Table 10.D
Feedrate Units
Unit/Interval
Abbreviation
Typically Used For:
millimeters per minute
mmpm
linear axis feedrates
inches per minute
ipm
linear axis feedrates
revolutions per minute
rpm
rotary axis feedrates
millimeters per rev
mmpr
threading
inches per rev
ipr
threading
In a metric part program for a linear axis, a feedrate of 100 millimeters per
minute (mmpm) typically would be written as F100.; (depending on the
active word format).
For details on programming feedrates by using the different feedrate
modes, see chapter 18. It also describes special preassigned feedrates.
Important: Feedrates programmed in any of the feedrate modes (G94 or
G95) can be overridden by use of the
The preparatory function is designated by a G-code consisting of address G
followed by a two-digit value. In some cases, the G-code may have an
additional decimal digit. Because many of these are set by industry
standards, they are usually referred to as G-codes. The G-codes are
classified as modal and non-modal.
Modal
the G-code remains in effect until another G-code in the same G-code group
is programmed.
Non-modal
the G-code is in effect only in the block in which it is programmed.
Important: When you program more than one G-code from the same
modal group in a block, the control executes the block as the G-codes
occur in the block sequentially from left to right. Any mode that is being
changed in a block only applies to the values to the right of the G-code.
Characters to the left of the G-code still use the old operating mode.
When the control executes an M02 or M30 code the system installer
determines in AMP if the modal M- and G-codes reset to their default
values. These default values become active at power up, E-STOP reset, or
control reset. Your system installer determines these defaults in AMP.
10.5.4
G-Codes (Preparatory
Functions)