Rockwell Automation 8520-MUM 9/Series CNC Mill Operation and Programming Manual Documentation Set - Manual (Page 299)

Introduction to Programming
Chapter 10
10-25
How the modal G-codes are executed is shown below, taking G00 and
G01, both classified into the same G--code group.
Example 10.9
Modal G- code Execution
G00 X1. Y2.; G00 mode is effective
Y3. ; G00 mode is in effect
G01 X2. Y1. F1; G01 mode is made effective
X3. Y3. ; G01 mode is in effect
G00 X1.Y2. ; G00 mode becomes effective again
G01 G00 Y3, ; G00 mode is in effect
G01 G91 Y2 ; G01 and G91 both in effect
An example of non-modal G-code execution follows:
Example 10.10
Non-Modal G- code Execution
G00 X1. Y21 ; G00 mode is effective
G28 X2.; G28 mode, this block only
X2. Y1. ; G00 mode is effective
G04 P2. ; G04 active this block only
Important: When programming more than one G-code from the same
modal group in a block, the control will execute the block as the G-codes
occur 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.
Example 10.11
Changing Modes Mid-Block
N10G90X10G91Y10; X10 is absolute (G90) Y10 is
incremental (G91).
N20X20; X20 is incremental (G91).
N30X30G90Y10; X30 is incremental (G91), Y10 is
absolute (G90).
N40M30
Table 10.E breaks down the G-codes into their modal groups. For
example, G-codes in group 01 are modal only with other G-codes in group
01. G-codes in the 00 group are non-modal and are effective only in the
block in which they are programmed.