This is a PLC Program to Implement a Combinational Logic Circuit (1).
The input to combinations logic circuit is a 4-bit binary number. Design the logic circuit with two outputs (Y1, Y2) for the following conditions. Also develop PLC program in Ladder Logic for the same.
Y1=1 if the input binary number is 5 or less than 5. Y2=1 if the input binary number is 9 or more than 9.
- To solve this problem, first the table showing ON state of Y1 and Y2 is created. (When Y1 or Y2 is 1).
- According to the table designed, Y1 and Y2 both will have different equations, Y1 when input binary number is 5 or less than 5 and Y2 when input is 9 or more than 9.
- To obtain these equations, Karnaugh-Map method is again used.
- By solving output expressions, we obtained minimized form of equation which is then applied into Ladder Diagram.
Output table and Karnaugh-Map method to solve Y1 and Y2 equations
Binary Inputs Outputs A B C D Y1 Y2 0 0 0 0 1 0 0 0 0 1 1 0 0 0 1 0 1 0 0 0 1 1 1 0 0 1 0 0 1 0 0 1 0 1 1 0 0 1 1 0 0 0 0 1 1 1 0 0 1 0 0 0 0 0 1 0 0 1 0 1 1 0 1 0 0 1 1 0 1 1 0 1 1 1 0 0 0 1 1 1 0 1 0 1 1 1 1 0 0 1 1 1 1 1 0 1
Combinational Circuit for outputs expressed using logic gates.
Here is PLC program to Implement a Combinational Logic Circuit, along with program explanation and run time test cases.
List of Inputs and Outputs
A = I:1/0 (Input) B = I:1/1 (Input) C = I:1/2 (Input) D = I:1/3 (Input) Y1= O:2/0 (Output) Y2= O:2/1 (Output)
Ladder Diagram to obtain combinational logic circuit output.
- Rung000 is to generate output Y1 which is 1 goes high or is set to 1 when Input Binary Number is 5 or less than 5.
- Rung001 is to generate output Y2 which goes high or is set to 1 when Input Binary Number is 9 or more than 9.
- In the given program, parallel connection shows ORing of inputs and series connection shows ANDing of inputs.
- Hence, output Y1 goes High/1 if any of the two conditions is fulfilled, whenever A (I:1/0) and B (I:1/1) both are Low/0 or whenever A (I:1/0) and C (I:1/2) both are Low/0.
- And accordingly, output Y2 goes high if any of the following conditions is fulfilled,
A (I:1/0) and B (I:1/1) both are High/1.
A (I:1/0) and C (I:1/2) both are High/1.
A (I:1/0) and D (I:1/3) both are High/1.
Input Number Binary Inputs Outputs A B C D Y1 Y2 0 0 0 0 0 1 0 1 0 0 0 1 1 0 2 0 0 1 0 1 0 3 0 0 1 1 1 0 4 0 1 0 0 1 0 5 0 1 0 1 1 0 6 0 1 1 0 0 0 7 0 1 1 1 0 0 8 1 0 0 0 0 0 9 1 0 0 1 0 1 10 1 0 1 0 0 1 11 1 0 1 1 0 1 12 1 1 0 0 0 1 13 1 1 0 1 0 1 14 1 1 1 0 0 1 15 1 1 1 1 0 1
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