Binary Coded Decimals Examples

This article is about Binary Coded Decimals Examples for PLC System concept learning. Read Also Previous Articles if you did not read before.

1. Lecture 1: What is Programmable Logic Controller in PLC?
2. Lecture 2: PLC Hardware Components – PC Information
3. Lecture 3: PLC Internal Architecture and Diagram Explanation
4. Lecture 4: What is PLC System? and Working Principle
5. Lecture 5: How to Connect Input Devices to PLC? Input Devices Examples
6. Lecture 6: How to Connect Output Devices to PLC? PLC Output Devices
7. Lecture 7: PLC Applications Examples And Solutions
8. Lecture 8: Numbering System in PLC (Digital System)
9. Lecture 9: The Binary System Concept in PLC
10. Lecture 10: Octal and Hexadecimal Numbering in PLC System

Binary Coded Decimals Examples

The binary coded decimal (BCD) system is an alternative method used to represent decimal numbers in binary form. In BCD, each decimal digit is separately encoded using four binary bits.

To convert a denary (decimal) number to BCD:

1. Convert each decimal digit to its corresponding 4-bit binary representation.
2. Write down the binary representation of each digit separately.

Example: Convert the denary number 15 to BCD:
1 -> 0001
5 -> 0101

The BCD representation of 15 is 0001 0101.

To convert a BCD number to a denary number:

1. Divide the BCD number into groups of four binary digits, starting from the leftmost digit.
2. Convert each group of four binary digits to its decimal equivalent.
3. Write down the decimal representation of each group separately.

Example: Convert the BCD number 0011 1001 to denary:
0011 -> 3
1001 -> 9

The denary representation of 0011 1001 is 39.

BCD is often used in numeric data entry systems where each digit is independently represented using rotary or thumb-wheel switches with a range of 0 to 9. Each switch’s output is then converted to BCD independently, resulting in a complete BCD number. Some PLCs have built-in functions to convert BCD numbers to binary, while in others, it needs to be done through programming.

Numbers in the Binary, Octal, Hex, and BCD Systems

Table 3.1 gives examples of numbers in the denary, binary, octal, hex, and BCD systems.

I hope this explanation clarifies the concept of Binary Coded Decimals (BCD). Let me know if you have any further questions!