Siemens SINUMERIK 828D Function Manual page 663

System variable
$AC_OLD_PROG_NET_TIME_COUNT
$AC_PROG_NET_TIME_TRIGGER
All system variables are reset to 0 as a result of POWER ON!
Basic Functions
Function Manual, 09/2011, 6FC5397-0BP40-2BA0
K1: Mode group, channel, program operation, reset response
Meaning
Changes to $AC_OLD_PROG_NET_TIME
After POWER ON, $AC_OLD_PROG_NET_TIME_COUNT is at "0".
$AC_OLD_PROG_NET_TIME_COUNT is always increased if the control has
newly written to $AC_OLD_PROG_NET_TIME.
If the user terminates the running program with RESET ,
$AC_OLD_PROG_NET_TIME and $AC_OLD_PROG_NET_TIME_COUNT
remain unchanged.
With $AC_OLD_PROG_NET_TIME_COUNT it can thus be ascertained,
whether $AC_OLD_PROG_NET_TIME was written.
Example:
If two programs running consecutively have the same runtime and were ended
correctly, then the user can identify this via the changed value in
$AC_OLD_PROG_NET_TIME_COUNT.
Trigger for the runtime measurement
Used for selective measurement of program sections i.e. by writing
$AC_PROG_NET_TIME_TRIGGER in the NC program the time measurement
can be enabled and disabled again:
1. $AC_PROG_NET_TIME_TRIGGER = 2 starts the measurement and in so
doing sets $AC_ACT_PROG_NET_TIME to "0".
2. $AC_PROG_NET_TIME_TRIGGER = 1 ends the measurement and copies
the value from $AC_ACT_PROG_NET_TIME into
$AC_OLD_PROG_NET_TIME.
In order to exploit all trigger options, specific values for
$AC_PROG_NET_TIME_TRIGGER are filled with special functions:
0 Neutral state
The trigger is not active.
1 Exit
Ends the measurement and copies the value from
$AC_ACT_PROG_NET_TIME into $AC_OLD_PROG_NET_TIME.
$AC_ACT_PROG_NET_TIME is set to "0" and then continues to run.
2 Start
Starts the measurement and in so doing sets
$AC_ACT_PROG_NET_TIME to "0". $AC_OLD_PROG_NET_TIME is not
changed.
3 Stop
Stops the measurement. Does not change $AC_OLD_PROG_NET_TIME
and keeps $AC_ACT_PROG_NET_TIME constant until it resumes
4 Resume
The measurement is resumed, i.e. a measurement that was previously
stopped is continued. $AC_ACT_PROG_NET_TIME continues to run.
$AC_OLD_PROG_NET_TIME is not changed.
9.16 Program runtime / Part counter
663