Combinational logic operation using AND gate and OR gate

Application:-Draw electrical diagram and write PLC program for combinational logic for 3 switches. Use AND gate and OR gate for three switches combinational logic. Operate lamp in the following condition,

If S1 or S2 is ON and S3 is ON, the lamp will be ON.

Components:-Programmable logic controller, Electrical panel, wires, 24VDC switches with NO contacts, 24VDC indication lamp, 24 VDC relay.


Diagram:-Electrical wiring diagram for combinational logic.

Explanation:-

Here we have 3 switches S1, S2, and S3. So the condition is either S1 or S2 should be ON or S3 should be ON. So S1 and S2 should be put in OR gate and this combination should be put in series with S3.

Hence the lamp will be ON if S1 or S 2 is ON and S3 is ON.

PLC program:-

Write the ladder program for combinational logic using ladder diagram language. Here for ladder logic, we can use any PLC system. For PLC logic we need digital inputs and outputs.

For our application, all switches are digital inputs, and the lamp is a digital output. To define digital input address and output address as per below explanation,

Digital inputs:-

S1=I0.0

S2=I0.1

S3=I0.2

Digital Output:-

Lamp=Q0.0

Memory coil:-

Memory bit-M0.0

PLC program Explanation:-

In-network 1 we have considered three digital inputs for three switches S1, S2, and S3. So we have taken NO contact of S1 (I0.0) and S2 (I0.1) in OR gate and. So when S1 or S2 OFF, memory bit (M0.0) will be ON.