Design Ladder Logic for Stair-Case wiring using two Toggle Switches in programmable logic controllers (PLC).
- I0.0 & I0.1 : Input toggle switches.
- Q0.0 : Output signaling device(bulb, motor etc.)
Ladder Logic for Stair-Case wiring
This ladder logic of stair-case wiring works on the X-OR logic i.e, Y is (A.B^) + (A^. B)
Suppose initially only I0.0 is pressed and I0.1 remains open physically as shown then the upper branch of rung 1 goes TRUE and Q0.0 gets energized.
Now , if I0.0 is also pressed then it will make its interlock N-C contact I0.1 to go open and as a result Q0.0 de-energizes .
Again, if switch I0.0 is pressed it will also make its interlock contact I0.0 in parallel branch to go again N-C , which in turn makes the parallel branch logic true and Q0.0 again energizes but if the I0.1 input is also pressed again the logic goes FALSE and Q0.0 again de-energizes. This is the basic concept of an X-OR logic gate.