on delay timer as a universal timer

any hint how i can make a pext or pulse timer using on delay timer in ladder logic. on delay timer is said to be a universal timer, all other timers can be made using on delay timer.

Which PLC?

S7-1215

aftab_khan said:

any hint how i can make a pext or pulse timer using on delay timer in ladder logic. on delay timer is said to be a universal timer, all other timers can be made using on delay timer.

Click to expand...

Depending on the length of the pulse and capability or speed of the timer instruction (1 millisecond,1 tenth second, 1 second, etc.), use two timers (TON) on two rungs. One (T1) would time the "On" time and the next rung (T2) would time the "Off" time. The closed "Done" bit from T2 resets both timers. Put the closed "Done " bit of T2 in the first rung. Use the open "Done" bit from the first timer (T1) to start the second timer (T2).
Use a third rung to output the On/Off pulse. This third rung uses a T1 contact open and a T2 contact closed, in series, to physical output.

Make a function block with an iec on delay timer in it.
Oneshot your input. Use the not of that pulse to drive the timer. The output is not pulse and not timer done.