Siemens SIMATIC S5 Manual page 124

IP 265
Timer operation
Starting a pulse timer "SI":
The timer is started each time the signal at the Start
input changes from "0" to "1", and runs until the
Start signal is "0", the time has expired or the timer is
reset.
Output Q is "1" as long as the timer is running, the
Start signal is "1" and the Reset signal is "0".
Example: Output Q 0.5 is set when input I 0.0
goes from "0" to "1", and is to remain
set for no more than 50 ms.
Starting an extended pulse timer "SE":
The timer is started (or retriggered) each time the
signal at the Start input goes from "0" to "1", and
runs until the set time has expired or the timer is
reset.
A "0" at the Start input does not affect the timer.
Output Q is "1" as long as the timer is running and
the Reset signal is "0".
Example: Output Q 0.5 is set for 50 ms as soon
as input I 0.0 goes from "0" to "1".
EWA 4NEB 812 6130-02a
Table 9-8. Timer Operations
Programming the IP 265 with COM 265
CSF (example)
1
> S
I 0.0
KT 5.0 TV
R Q
Timing diagram
Signal states
1
0
1
0
50
1 V
> S
I 0.0
KT 5.0 TV
R Q
Timing diagram
Signal states
1
0
1
0
50
Q 0.5
I 0.0
Q 0.5
Time in ms
Q 0.5
I 0.0
Q 0.5
50 Time in ms
9-19