Timer Variable ($Ac_Timer[N]) - Siemens SINUMERIK 840D sl Programming Manual

10.3.9

Timer variable ($AC_Timer[n])

Function
System variable $AC_TIMER[n] permits actions to be started after defined periods of delay.
Timer variable: Data type:REAL
$AC_TIMER[n]
s
n
Setting timers
Incrementation of a timer variable is started by means of value assignment:
$AC_TIMER[n]=value
n :
value:
Stopping timers
Incrementation of a timer variable can be stopped by assigning a negative value:
$AC_TIMER[n]=-1
Reading timers
The current timer value can be read whether the timer variable is running or has been
stopped. After a timer variable has been stopped through the assignment of -1, the current
time value remains stored and can be read.
Example
Output of an actual value via analog output 500 ms after detection of a digital input:
Program code
WHEN $A_IN[1] == 1 DO $AC_TIMER[1]=0
WHEN $AC_TIMER[1]>=0.5 DO $A_OUTA[3]=$AA_IM[X] $AC_TIMER[1]=-1
Job Planning
Programming Manual, 06/2009, 6FC5398-2BP20-0BA0
Channel-specific timer of data type REAL
Unit in seconds
Index of timer variable
Number of time variables
Starting value (generally "0")
Motion synchronous actions
10.3 Main run variables for synchronized actions
Comments
; Reset and start timer
657