Chapter 9 
160 
Logic programming – Function blocks 
 
9.8.5 On-delay timer 
Function block diagram 
 
 
General description 
The On-delay timer function block delays the switching-on of the output signal by a 
specified duration. 
Parameters of the function block 
Parameter  Possible values 
Delay time  0 = disabled. 
0 to 300 seconds in steps of 10 ms. 
If the value is not 0, it has to be greater than the logic execution time. 
 
The timer begins with the delay sequence when a rising edge (Low to High) on the 
input occurs. If the timer has expired after the configured delay period, the Enable 
output changes also to High, provided the input remains High. If the input changes to 
Low, the Enable output is set to Low immediately and the delay timer is reset. 
 
Sequence/timing diagram 
 
 
Figure 140: 
Function block diagram for 
the On-delay timer function 
block 
Table 67: 
 Parameters of the On-delay 
timer function block 
Figure 141:   
Sequence/timing diagram 
for the On-delay timer 
function block