Binary to BCD Conversion in PLC

This is a PLC Program to Implement Binary to BCD Converter.

Problem Description

Implementing Binary to BCD converter in PLC using Ladder Diagram programming language.

Problem Solution
  • Writing truth table showing the relation between Binary as input and BCD as output.
  • To obtain these equations, Karnaugh-Map method is again used.
  • For each BCD output D4, D3, D2, D1 and D0, write Karnaugh-Map.
  • From the K-Map, obtaining a simplified expression for each BCD output in terms of Binary inputs.
  • Realize the code converter using the Logic Gates.
  • And from the same simplified expressions, draw a Ladder Diagram to obtain BCD output in terms of Binary inputs.

Truth Table relating Binary to BCD

Decimal	Binary input	                BCD output
	B3	B2	B1	B0	D4	D3	D2	D2	D0
0	0	0	0	0	0	0	0	0	0
1	0	0	0	1	0	0	0	0	1
2	0	0	1	0	0	0	0	1	0
3	0	0	1	1	0	0	0	1	1
4	0	1	0	0	0	0	1	0	0
5	0	1	0	1	0	0	1	0	1
6	0	1	1	0	0	0	1	1	0
7	0	1	1	1	0	0	1	1	1
8	1	0	0	0	0	1	0	0	0
9	1	0	0	1	0	1	0	0	1
10	1	0	1	0	1	0	0	0	0
11	1	0	1	1	1	0	0	0	1
12	1	1	0	0	1	0	0	1	0
13	1	1	0	1	1	0	0	1	1
14	1	1	1	0	1	0	1	0	0
15	1	1	1	1	1	0	1	0	1

Boolean expression for each BCD bits can be written as

 D4= m(10, 11, 12, 13, 14, 15)
 D3= m(8, 9)
 D2= m(4, 5, 6, 7, 14, 15)
 D1= m(2, 3, 6, 7, 12, 13)
 D0= m(1, 3, 5, 7, 9, 11, 13, 15)

plc-program-implement-binary-bcd-converter-01
plc-program-implement-binary-bcd-converter-02

advertisement
advertisement

Realizing code conversion using Logic Gates
plc-program-implement-binary-bcd-converter-03

PLC Program

Here is PLC program to Implement Binary to BCD Converter, along with program explanation and run time test cases.

List of Inputs and Outputs
 B3=		I:1/0	(Input)
 B2=		I:1/1	(Input)
 B1=		I:1/2	(Input)
 B0=		I:1/3	(Input)
 D4=		O:2/0	(Output)
 D3=		O:2/1	(Output)
 D2=		O:2/2	(Output)
 D1=		O:2/3	(Output)
 D0=		O:2/4	(Output)

Ladder Diagram to obtain BCD output
plc-program-implement-binary-bcd-converter-04

Program Description
  • D4 is MSB bit of BCD output.
  • D3 is 2nd bit of BCD output and so are similarly D2, D1 and D0, 3rd, 4th and LSB of BCD output respectively.
  • B3 to B0 are 4 Binary inputs which are converted into BCD numbers.
  • RUNG000 is used for D4 bit and so on till RUNG004 which is used for LSB D0.
  • As we apply any 4bit binary input, B3 to B0 are set to 1 such that D4 to D0 bits go high according to BCD patterns of the applied Binary input.
Runtime Test Cases
Hexa-
Decimal	Decimal	Binary input	                BCD output
		B3	B2	B1	B0	D4	D3	D2	D2	D0
0	0	0	0	0	0	0	0	0	0	0
1	1	0	0	0	1	0	0	0	0	1
2	2	0	0	1	0	0	0	0	1	0
3	3	0	0	1	1	0	0	0	1	1
4	4	0	1	0	0	0	0	1	0	0
5	5	0	1	0	1	0	0	1	0	1
6	6	0	1	1	0	0	0	1	1	0
7	7	0	1	1	1	0	0	1	1	1
8	8	1	0	0	0	0	1	0	0	0
9	9	1	0	0	1	0	1	0	0	1
A	10	1	0	1	0	1	0	0	0	0
B	11	1	0	1	1	1	0	0	0	1
C	12	1	1	0	0	1	0	0	1	0
D	13	1	1	0	1	1	0	0	1	1
E	14	1	1	1	0	1	0	1	0	0
F	15	1	1	1	1	1	0	1	0	1

Sanfoundry Global Education & Learning Series – PLC Algorithms.

advertisement

To practice all PLC programs, here is complete set of 100+ PLC Problems and Solutions.

advertisement
If you find any mistake above, kindly email to [email protected]

advertisement
advertisement
Subscribe to our Newsletters (Subject-wise). Participate in the Sanfoundry Certification contest to get free Certificate of Merit. Join our social networks below and stay updated with latest contests, videos, internships and jobs!

Youtube | Telegram | LinkedIn | Instagram | Facebook | Twitter | Pinterest
Manish Bhojasia - Founder & CTO at Sanfoundry
Manish Bhojasia, a technology veteran with 20+ years @ Cisco & Wipro, is Founder and CTO at Sanfoundry. He lives in Bangalore, and focuses on development of Linux Kernel, SAN Technologies, Advanced C, Data Structures & Alogrithms. Stay connected with him at LinkedIn.

Subscribe to his free Masterclasses at Youtube & discussions at Telegram SanfoundryClasses.