RS-485 Bus Overview When the communication distance is required to be from tens to thousands of meters, the RS-485 serial bus standard is widely used. RS-485 uses balanced transmission and differential reception, thus it has the ability to suppress common-mode interference. Additionally, the bus transceiver has high sensitivity and can detect voltages as low as … Read more
Today, I would like to share a document from TI titled “RS-485 Design Guide”, which can serve as an introduction. The document link is as follows: https://www.ti.com.cn/cn/lit/pdf/zhcaa89 1 Introduction In 1983, the Electronic Industries Association (EIA) approved a new balanced transmission standard known as RS-485. It was found that RS-485 was highly praised and widely … Read more
The RS-485 bus has advantages such as a simple structure and low cost. However, when engineers set up RS-485 bus networks, they often encounter the question: should termination resistors be added to improve the reliability of the entire network’s communication? This article will answer that question. 1. The Role of Termination Resistors For the RS-485 … Read more
01 【Overview of RS-485】 RS-485, like RS-232, is a serial communication standard. The current standard name is TIA485/EIA-485-A, but it is commonly referred to as the RS-485 standard. RS-485 is widely used in industries such as automation, automotive, and building management. The RS-485 bus overcomes the shortcomings of RS-232’s short communication distance and low speed. … Read more
This article introduces the correct connection method for RS-485 networks, including suggestions for twisted pair wiring and proper installation of termination resistors. It lists the receiver waveforms under correct and incorrect termination. Configurations from simple single transmitter/multiple receiver networks to multiple transceivers and multiple branch circuits are provided. This article can serve as a basic … Read more
The RS-485 bus is widely used in communication, industrial automation, and other fields. In practical applications, we often encounter the question of whether to add pull-up and pull-down resistors and what size of resistors is appropriate. Below, we will conduct a detailed analysis of these issues. 1. Why Are Pull-Up and Pull-Down Resistors Needed? 1. … Read more
Click the “Technical Training” above and select “Top Official Account“ 170,000+ industrial control professionals follow the WeChat platform: technical sharing, learning exchange, industrial control videos 01 Number of Connections The S7-200 SMART CPU can connect to Siemens HMI devices that support the PPI protocol through the integrated RS485 port or signal board, or it can … Read more
Click↑↑Technical Training, follow and pinto subscribe for free long-term 180,000+Industrial control professionals follow this WeChat platform: technical sharing, learning exchange, industrial control videos After establishing RS-485 communication between the inverter and PLC, commands sent by the PLC via the communication cable can be received. If multiple inverters are connected to the PLC via RS-485, each … Read more
Profibus PA (Process Automation Bus) is one of the most important field communication protocols in the process industry. It is designed for complex industrial environments and provides stable and efficient data transmission under harsh production conditions. This article will delve into the key features and application value of Profibus PA, helping readers gain a comprehensive … Read more
PROFIBUS Transmission Technology (Physical Layer) and DP Communication In the ISO/OSI reference model, the first layer defines the “physical” methods of data transmission. This includes encoding types and the transmission standards used (e.g., RS 485). PROFIBUS provides various transmission technologies for the first layer: RS 485, RS 485-IS, MBP, and fiber optic transmission technology. Traditional … Read more