Siemens Sinumerik 840D sl Programming Manual page 637

Sequence
Technology cycles are started as soon as their conditions have been fulfilled. Each line in a
technology cycle is processed in a separate IPO cycle. Several IPO cycles are required to
execute positioning axes. Other functions are executed in one cycle. Blocks are sequentially
executed in the technology cycle.
If actions that are mutually exclusive are called up in the same interpolation cycle, the action
that is called up from the synchronized action with the higher ID number becomes active.
Examples
Example 1: Axis programs are started by setting digital inputs
Main program:
Program code
ID=1 EVERY $A_IN[1]==1 DO AXIS_X
ID=2 EVERY $A_IN[2]==1 DO AXIS_Y
ID=3 EVERY $A_IN[3]==1 DO AXIS_Z
M30
Axis program AXIS_X:
Program code
M100
POS[X]=100 FA[X]=300
M17
Job planning
Programming Manual, 02/2011, 6FC5398-2BP40-1BA0
Comments
; If input 1 is 1, start axis program AXIS_X.
; If input 2 is 1, start axis program AXIS_Y.
; If input 3 is 1, start axis program AXIS_Z.
Motion synchronous actions
10.5 Technology cycles
637