72 Write a documented program that will simulate the offdela

7-2 Write a documented program that will simulate the off-delay relay timer schematic shown. Use the I/O Simulator screen and the following addresses to simulate the program: S1 _ I:1/0 L1 _ O:2/0 TON _ T4:0

L1 2 S1 TD TD1 L1 Sequence of operation: S1 open, TD de-energized. TD1 closed, L1 or. S1 closes, TD energizes, TD1 opens instantly, L1 is switched off. S1 is opened. TD de-energizes, timing period starts, TD1 is still open, L1 is still off. After 10 s, TD1 cioses, L1 is switched on.

Solution

patter of switchin is that

O.CO.O.t.C

i.e S1 is open to de energise

and close to energise TD1

further it is open for 10 sec to completely de energise

then closed to further energise