This is a PLC Program to Implement 3 to 8 Line Decoder.
Problem Description
Implement 3 to 8 line decoder in PLC using Ladder Diagram programming language.
Problem Solution
- It has three inputs I0, I1 and I2 and 8 outputs Q0 to Q7.
- These three inputs I0, I1 and I2 determines which output should be active.
- If I0 and I1 are true and I2 is false, then Q6 will be activated and all others are not.
- It does not need K-map and simplification so one step is eliminated to create Ladder Logic Diagram.
- Realize the 3 to 8 line decoder using Logic Gates.
Truth Table can be written as given below.
Inputs Outputs I2 I1 I0 Q0 Q1 Q2 Q3 Q4 Q5 Q6 Q7 0 0 0 1 0 0 0 0 0 0 0 0 0 1 0 1 0 0 0 0 0 0 0 1 0 0 0 1 0 0 0 0 0 0 1 1 0 0 0 1 0 0 0 0 1 0 0 0 0 0 0 1 0 0 0 1 0 1 0 0 0 0 0 1 0 0 1 1 0 0 0 0 0 0 0 1 0 1 1 1 0 0 0 0 0 0 0 1
Realization of 3 to 8 line decoder using Logic Gates
PLC Program
Here is PLC program to Implement 3 to 8 Line Decoder, along with program explanation and run time test cases.
advertisement
List of Inputs and Outputs I0= I:1/0 (Input) I1= I:1/1 (Input) I2= I:1/2 (Input) Q0= O:2/0 (Output) Q1= O:2/1 (Output) Q2= O:2/2 (Output) Q3= O:2/3 (Output) Q4= O:2/4 (Output) Q5= O:2/5 (Output) Q6= O:2/6 (Output) Q7= O:2/7 (Output)
Ladder Diagram for 3 to 8 line decoder
Program Description
- In all the rungs, I0 (I:1/0), I1 (I:1/1) and I2 (I:1/2) are used to determine which output from Q0 to Q7 should go ON..
- Q0 to Q7 are outputs.
- When I0 (I:1/0), I1 (I:1/1) and I2 (I:1/2) are low, output 0 O:2/0 will get activated.
- When I:1/0 and I:1/1 are low and I:1/1 is high that is when I0 and I1 are low and I2 is high, output 1 O:2/1 will get activated.
- Similarly remaining six different outputs are obtained.
- In other words, according to bit pattern of I0 I:1/0, I1 I:1/1 and I2 I:1/2, outputs from Q0 to Q7 are activated.
Runtime Test Cases
Inputs Outputs I2 I1 I0 Q0 Q1 Q2 Q3 Q4 Q5 Q6 Q7 0 0 0 1 0 0 0 0 0 0 0 0 0 1 0 1 0 0 0 0 0 0 0 1 0 0 0 1 0 0 0 0 0 0 1 1 0 0 0 1 0 0 0 0 1 0 0 0 0 0 0 1 0 0 0 1 0 1 0 0 0 0 0 1 0 0 1 1 0 0 0 0 0 0 0 1 0 1 1 1 0 0 0 0 0 0 0 1
Sanfoundry Global Education & Learning Series – PLC Algorithms.
To practice all PLC programs, here is complete set of 100+ PLC Problems and Solutions.