(1) Introduction RS-485 is a balanced transmission standard for serial communication approved by the Electronic Industries Alliance in the United States in 1983. It only specifies the electrical characteristics of drivers and receivers without defining a protocol; therefore, many higher-level interface standards refer to RS-485 at the physical layer, such as Modbus, Profibus, etc. (2) … Read more
Any communication interface testing includes two parts: basic electrical characteristic testing and stress testing. RS-485 is no exception. The common tests for RS-485 primarily focus on electrical characteristic testing and stress testing. The first part: Electrical Testing. For electrical testing, we generally combine some parameters from the chip manual for testing. The following figure shows … Read more
How to Design a Modular Host Computer? Why is there such a big difference in the situation of engineers at home and abroad? Easy Learning of TIA Portal SCL Programming Structured Variables Understand S7-1500 PLC Reading and Writing SQL Microsoft Database in Seconds 1. Device Functionality Among various schemes for medium to long distance communication … Read more
Abstract: This design guide discusses how to design RS-485 interface circuits. It covers the necessity of balanced transmission line standards and provides an example of a process control design. The article also discusses line loading, signal attenuation, failure protection, and current isolation under different headings. 1 Why Balanced Transmission Line Standards Are Needed This article … Read more
RS-485, with its excellent ability to resist common mode noise, is suitable for long-distance signal transmission, especially widely used in industrial environments. This article introduces the working principle of RS-485 and the EMI risks it faces (electrostatic interference, electrical fast transient bursts, and surge voltage), and discusses several EMC solutions that help RS-485 cope with … Read more
Among the various solutions for medium to long-distance communication between MCUs, RS-485 is widely used in factory automation, industrial control, community monitoring, and water resources automatic reporting due to its simple hardware design, ease of control, and low cost. However, RS-485 bus still has defects in anti-interference, adaptability, and communication efficiency. Improper handling of some … Read more
With the popularization of the concept of “carbon neutrality”, industries such as photovoltaics, wind power, and energy storage are once again ushering in a boom. As a commonly used communication interface in these industries, RS-485 often requires additional protection circuits to ensure stable communication. This article will introduce a protection circuit scheme for multi-node environments. … Read more
For more information on RS-485, you can also refer to some previous articles in our series: 1. Please check out this comprehensive RS-485 beginner’s guide!2. From beginner to advanced applications! Say goodbye to using RS-485 without understanding it! 3. What projects to test with RS-485, and how to test them? ▉ Overview of RS-485 RS-485, … Read more
Table of Contents 1. Key Technical Features of RS-485 2. Application Scenarios 3. Standards 4. Advantages of Using Differential Signal Transmission 5. Similarities and Differences Between RS-422 and RS-485 5.1 Differences in Bus Architecture 5.2 Differences in Common Mode Voltage Range 5.3 Differences in Input Impedance of Receivers 5.4 RS-485 Transceivers with Enable Pins 6. … Read more
Hidden Costs of Isolated RS-485 Optocoupler Design Optocouplers, also known as optical isolators or optoelectronic couplers, have been used for over 40 years to achieve current isolation in electronic circuits. Optocouplers use LEDs and phototransistors to communicate signals without transmitting current. As a low-cost solution, optocouplers have remained popular. But considering the advancements in digital … Read more