Siemens SINUMERIK 840D sl Programming Manual page 985

Note
Residual time for a workpiece
If the same workpieces are machined one after the other, using the following timer values, the
remaining residual time for a workpiece can be determined.
● Processing time for the last workpiece produced (see $AC_OLD_PROG_NET_TIME)
● Current processing time (see $AC_ACT_PROG_NET_TIME)
The residual time is displayed on the user interface in addition to the current processing time.
Note
Using STOPRE
The system variables $AC_OLD_PROG_NET_TIME and
$AC_OLD_PROG_NET_TIME_COUNT do not generate any implicit preprocessing stop. This
is uncritical when used in the part program if the value of the system variables comes from the
previous program run. However, if the trigger for the runtime measurement
($AC_PROG_NET_TIME_TRIGGER) is written very frequently and as a result
$AC_OLD_PROG_NET_TIME changes very frequently, then an explicit STOPRE should be
used in the part program.
Supplementary conditions
● Block search
No program runtimes are determined through block searches.
● REPOS
The duration of a REPOS process is added to the current processing time
($AC_ACT_PROG_NET_TIME).
Examples
Example 1: Measuring the duration of "mySubProgrammA"
Program code
...
N50 DO $AC_PROG_NET_TIME_TRIGGER=2
N60 FOR ii= 0 TO 300
N70 mySubProgrammA
N80 DO $AC_PROG_NET_TIME_TRIGGER=1
N95 ENDFOR
N97 mySubProgrammB
N98 M30
After the program has processed line N80, the net runtime of "mySubProgrammA" is located in
$AC_OLD_PROG_NET_TIME.
NC programming
Programming Manual, 12/2019, 6FC5398-2EP40-0BA0
Work preparation
3.22 Program runtime/part counter
985