Learn 4-20 Ma Analog Signals In Plc Systems For Beginners

PLC Basics, Electrical & Instrumentation Course, Understand 4-20 mA Signals

What you'll learn

Understand the fundamentals of analog signals.

Basics of PLC Automation.

Learn why 4 mA and 20 mA specific limits are chosen for analog signal ranges.

Understand why 4-20 mA is used in electrical and instrumentation systems.

Advantages and disadvantages of 4-20 mA current signals.

Learn about industry standards and best practices

Requirements

No prior experience in automation, electrical or instrumentation required.

Basic understanding of industrial automation concepts is helpful but not necessary.

Anyone interested in learning about 4-20 mA analog signal transmission in PLC.

Description

The 4-20mA current loop is the backbone of industrial automation and process control. From PLC (Programmable Logic Controller) systems to sensor-based instrumentation, 4-20mA signals play a vital role in transmitting accurate and noise-resistant data across long distances. But have you ever wondered why 4-20mA was chosen? Why not 0-10V, 0-20mA, or any other range?This Electrical and Instrumentation Basic Course is designed to provide a deep understanding of the 4-20mA standard, explaining its origin, advantages, disadvantages, and why it dominates the industry today. This basic course helps engineers, technicians, students, or automation enthusiasts to learn the fundamentals of this essential 4-20 mA signal transmission method.Why Learn About 4-20mA?Industrial sensors, actuators, and controllers rely on accurate signal transmission to maintain precision and efficiency. The 4-20mA current loop ensures that data remains stable, interference-free, and consistent—even across long distances. Learning about this fundamental technology helps professionals troubleshoot, optimize, and design better control systems.What You’ll LearnWhy 4-20mA?: The history and reasoning behind choosing 4-20mA over other signals.Origins of 4-20 mA: Understand why 4 mA serves as the “live zero” and 20 mA is chosen as the upper limit.Advantages & Disadvantages: Explore how 4-20 mA reduces noise interference, ensures reliable signal transmission, and why it sometimes needs extra components for voltage-based systems.Why 4-20mA is used in PLCs?: How PLCs process analog input signals.Practical Applications: See real-world examples of 4-20 mA in process control, industrial instrumentation, and sensor feedback loops.Why It’s Widely Adopted: Discover how 4-20 mA maintains accuracy over long distances, powering many field devices without extra wiring.Who Should EnrollThis course is perfect for beginners, professionals, engineering students, engineers & technicians, or anyone eager to learn the core principles of 4-20 mA in electrical and instrumentation systems.By the end of this course, you’ll know exactly why 4-20 mA is central to industrial electronics and instrumentation engineering, and how to apply it in your own projects or career. Join us to unlock the secrets behind the most trusted current loop in the industry!

Overview

Section 1: Introduction to PLC Automation

Lecture 1 The Industrial Plant

Lecture 2 Control Room

Lecture 3 4-20 mA Overview in PLC Systems

Lecture 4 Tank Level Measurement

Lecture 5 Industry Live Example

Lecture 6 Analog Inputs in PLC

Lecture 7 Pump Control

Lecture 8 Analog Outputs in PLC

Lecture 9 4-20 mA Questions

Section 2: PLC Analog Signals Concept

Lecture 10 Dead Zero Problem

Lecture 11 Live Zero Advantage

Lecture 12 Question: Why 4 mA? Why Not 0 mA?

Lecture 13 Introduction to Bias

Lecture 14 Early Transistor & Circuit Limitations

Lecture 15 Question: Why 4 mA? Why Not 2 mA?

Section 3: History of Systems

Lecture 16 Pneumatic Control Systems

Lecture 17 Analog Systems

Lecture 18 I/P and P/I Converters

Lecture 19 Transition from Pneumatic to Analog Instruments

Lecture 20 Application Example 1

Lecture 21 Application Example 2

Lecture 22 Application Example 3

Lecture 23 Application Example 4

Section 4: Why 4 mA Reference is Standard?

Lecture 24 Design Rule for 4 mA Selection

Lecture 25 Why 20% Bias Rule?

Lecture 26 Question: Why 4 mA? Why Not 6 mA or 10 mA?

Lecture 27 Upper Range Value

Section 5: Why 20 mA is used in PLC Systems?

Lecture 28 Human Safety

Lecture 29 Question: Why 20 mA? Why Not 30 mA?

Lecture 30 Design Rule for 20 mA Selection

Lecture 31 Why 1:5 Ratio?

Lecture 32 Question: Why 20 mA? Why Not 25 mA or 15 mA?

Lecture 33 Lower Range Value

Section 6: 4-20 mA Industry Standard

Lecture 34 Easy I to V Conversion

Lecture 35 Why I to V Conversion?

Lecture 36 Question: Why 4 to 20 mA Range?

Section 7: Quick Facts

Lecture 37 Before 4-20 mA Signals

Section 8: Advantages of 4-20 mA Analog Signals

Lecture 38 Fault Detection

Lecture 39 Long Distance Transmission

Lecture 40 Simple & Cost-Effective Wiring

Lecture 41 Less Affected by Noise & Interference

Lecture 42 Supports Loop-Powered Devices

Lecture 43 Simple Current to Voltage Conversion

Lecture 44 Worldwide Industry Standard

Section 9: Disadvantages of 4-20 mA Analog Signals

Lecture 45 Magnetic Field and Crosstalk Problems

Lecture 46 Twisted Pair Cables Solution

Lecture 47 Limited to Single Measurement

Section 10: The End

Lecture 48 Conclusion

Beginners learning 4-20 mA in electrical & instrumentation.,PLC professionals enhancing analog signals knowledge.,Engineering students exploring process control & automation.,Technicians working with sensors & industrial signals.,Anyone curious about why 4-20 mA is the industry standard.