Rockwell Automation 8520-MUM 9/Series CNC Mill Operation and Programming Manual Documentation Set - Manual (Page 779)

Chapter 30
Using a 9/Series Dual--processing System
30-11
Synchronization in MDI Mode
Synchronization M-codes can be programmed in MDI mode. These can
prove useful when attempting to manually start multiple programs from
some point other than the beginning or when it is necessary to execute
MDI programs on both processes simultaneously. By inserting a
synchronization M-code (by using MDI and pressing cycle start) you can
start a process executing, but place it in pause until you start the second
process and it executes the corresponding synchronization code.
Example 30.5
Synchronization in MDI Mode
Process 1 (MDI mode) Comment Process 2 (MDI mode) Comment
N1 M100; You can press <CYCLE START> and
this block pauses while you MDI the
necessary information into process 2.
N1 M100; Pressing <CYCLE START> at this block
has the effect of starting both processes’
MDI program at the same time.
G28 X10 Z10;
G28 X10 Z10;
Program Interrupts During Synchronization Blocks
Program interrupts can be performed while a process is being paused by a
synchronization M-code (see chapter 29 for details on interrupts). If the
process is paused when the interrupt is requested, the request is recognized;
however, the interrupt does not execute until the synchronization M-code is
released by the other process, executing the appropriate synchronization
code.
<CYCLE STOP> During Synchronization Blocks
Press <CYCLE STOP> places in cycle suspend mode while it is paused by
a synchronization M-code. This lets you perform most manual operations
(such as jog retract) and other functions normally available to a process in
cycle suspend mode. No loss of synchronization occurs while the process
is in cycle suspend.
Block retrace does not retrace through part program blocks with
synchronization M-codes in them. The error message “NO FURTHER
RETRACE ALLOWED” appears.