Why Is the CAN Bus Termination Resistor 120Ω?

Why Is the CAN Bus Termination Resistor 120Ω?

Source | Vehicle Terminal Function of the Termination Resistor The CAN bus termination resistor serves three purposes: 1. Enhance anti-interference capability, allowing high-frequency low-energy signals to dissipate quickly. 2. Ensure the bus quickly enters a dormant state, allowing the energy of parasitic capacitance to dissipate faster; 3. Improve signal quality, placed at both ends of … Read more

Analysis of Missing Termination Resistor Phenomenon in CAN Bus

Analysis of Missing Termination Resistor Phenomenon in CAN Bus

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

Why Is the CAN Bus Termination Resistor 120Ω?

Why Is the CAN Bus Termination Resistor 120Ω?

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

Impact of Not Using Termination Resistors in CAN Bus

Impact of Not Using Termination Resistors in CAN Bus

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

The Role of Termination Resistors in PROFIBUS-DP Connectors

The Role of Termination Resistors in PROFIBUS-DP Connectors

*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

Choosing RS-485 Bias and Termination Resistors

Choosing RS-485 Bias and Termination Resistors

RS-485 automatic transceiver circuits are favored because they use one less I/O pin compared to circuits with control pins, making them more popular in resource-constrained master control scenarios. How does the automatic transceiver achieve automatic sending and receiving, and what factors should be considered when selecting bias and termination resistors? RS-485 Automatic Transceiver Principle The … Read more

How to Add Termination Resistors in RS-485 Networks

How to Add Termination Resistors in RS-485 Networks

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

Correct Connection Method for RS-485 Networks

Correct Connection Method for RS-485 Networks

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