When testing the CAN bus in vehicles, we find that the resistance between the CAN buses in the vehicle is around 60 ohms. When testing a specific ECU CAN bus on a test bench, we may find that some ECUs have a resistance of 120 ohms, while others do not have any. Why does this … Read more
Friends in “Vehicle Technology” should know that the CAN bus requires two 120 Ohm termination resistors at both ends, making the total line resistance 60 Ohms. This is a piece of knowledge that almost everyone knows, but very few can explain clearly. In most cases, we have the experience that adding a 120 Ohm resistor … Read more
To build a stable and reliable Profibus-DP network, termination resistors can be considered a “small component with a big role”! Many engineers often overlook their importance, resulting in spending several days troubleshooting inexplicable communication failures, only to find out that it was the termination resistors causing the trouble. Today, we will analyze this seemingly simple … Read more
In a Profibus-DP network, the bus length is one of the key factors affecting system stability. As the bus length increases, signal attenuation, delay, and interference also increase, which changes the requirements for termination resistors. Today, we will discuss in detail how to correctly choose and install termination resistors for different lengths of Profibus-DP buses. … Read more
Abstract This article introduces the correct connection methods for RS-485 networks, including twisted pair wiring and recommendations for proper installation of termination resistors. It lists the receiver waveforms under correct and incorrect termination. This application note provides a basic guide for connecting RS-485 networks. The RS-485 specification (officially known as TIA/EIA-485-A) does not specifically dictate … Read more
PROFIBUS Physical Wiring and DP Connector Diagram From the diagram, it can be seen that when the switch is turned to “ON”, terminals A1 and B1 are connected to the termination resistor, so only A1 and B1 can be connected at the end of the DP network; otherwise, the termination resistor cannot be connected. When … Read more
Source:Automotive Chassis Home Requirements for Adding Termination Resistors According to ISO11898-2 regulations on the value of termination resistors, a 120Ω termination resistor must be connected at both ends of the bus, totaling 60Ω on the bus, while intermediate nodes do not require termination resistors, as shown in Figure 1. Figure 1 Termination Resistor Effects of … Read more
The termination resistor for the CAN bus is generally 120 ohms. In fact, during design, it consists of two 60 ohm resistors connected in series. There are typically two nodes of 120Ω on the bus, which is a well-known fact for anyone with a basic understanding of the CAN bus. However, as someone who struggles … Read more
Before performing CAN bus communication, it is important to ensure proper bus configuration, such as termination resistors. They are crucial components that affect bus communication. Below, we will analyze the effects of not using termination resistors solely from the perspective of signal amplitude and time constant, without considering signal integrity. Termination Resistor Requirements According to … Read more
*Follow to receive 2798 PLC wireless communication cases* The PROFIBUS bus is a purple shielded twisted pair cable, with the two cores being red and green. When connecting to the bus connector, the wiring must be done according to color, generally A1 and A2 are green, while B1 and B2 are red. 2. Devices on … Read more