Siemens SINUMERIK 840Di sl Function Manual page 17

Examples:
WHENEVER ($A_IN[1]==1) OR ($A_IN[3]==0) DO ...
; while input 1 is applied or input 3 is not applied ...
Two or more real-time expressions may be compared with one another within one condition.
Comparisons may be made between variables of the same type or between partial
expressions.
Examples:
Example
WHEN $AA_IM[X2] <= $AA_IM[X1] +.5 DO $AA_OVR[X1]=0
; Stop, when the safety clearance is exceeded.
Further examples of conditions can be found in Chapter 6.1. The calculations of real-time
expressions are described in the Chapter "Evaluations and calculations in real time".
All system variables whose data are read or written by the NC via synchronized actions can
be addressed in conditions. So can all machine data and setting data where the value is
read in the main run:
Machine data, e.g. $$MN_..., $$MC_..., $$MA_...
Setting data, e.g. $$SN_..., $$SC_..., $$SA_...
Note
GUD variables cannot be used
R-parameters are addressed with $R... .
Setting data and machine data, whose value may vary during machining, must be
programmed with $$S._.../$$M._... .
More examples of conditions are given in the Chapter "Examples for conditions in
synchronized actions".
G code for the action
The G code may specify a different G code from the condition for all actions in the block and
technology cycles. If technology cycles are contained in the action part, the G code remains
modally active for all actions until the next G code, even after the technology cycle has been
completed.
Only one G code of the G code group may be programmed for each action part.
Synchronized actions
Function Manual, 11/2006, 6FC5397-5BP10-2BA0
Detailed description
2.1 Components of synchronized actions
17