Talk about CANbus voltage

First, let's talk about can. It is the Chinese translation of controller area network, invented by Bosch Company in Germany, and is mainly used in the development of automobile electronic products. Later, because of its fast data transmission speed, strong anti-interference ability, and many connecting node devices, it was also applied in the fields of fire fighting host networking, artificial intelligence development, industrial automation production, etc., known as the most promising industrial bus. The information transmission mode of CAN bus is differential voltage signal transmission, that is to say, the information transmission of CAN bus is supported by two wires twined together. One of the two wires has a high voltage, so we can call it can high. The voltage of the other wire is naturally lower, so we call it can low. Because there is a high-low gap in the voltage between the two wires, the high side will push the low side to move, just like we used to learn about atmospheric pressure, the principle is almost the same. The information transmitted on the CAN bus is actually the voltage difference between the two wires. This is also the reason that can bus has the ability of strong anti-interference. After all, no matter how disturbed you may be, you can't just keep the voltage between the two wires at the same level. As long as there is a voltage difference between the two wires, the CAN bus can transmit information, unless there are some special circumstances. For example, the external interference is too large, which exceeds the maximum range of CAN bus, and the whole system is damaged. Or, the connected voltage is too large, and the components of the equipment are burnt out.

Generally speaking, the CAN bus used for relay or data conversion equipment only supports 9-30v voltage value. If it does not reach this value, the equipment cannot operate, and the components in the equipment exceeding this value will be burned. Therefore, the 110V or even 220V power supply that threatens our life safety should not be directly connected to relevant equipment. We need special transformer equipment to reduce the voltage to 9-30v. Note that it is the power supply of the power supply, which is not what can bus needs to bear. Because some can gateway equipment or can analyzer equipment's power interface and can bus interface are terminals, sometimes we do not pay attention to observation before connecting, it is easy to insert the power terminal into the can interface, at that time, even if your power voltage is only 30V, it will cause irreparable consequences.
 

 

There is no need to pay attention to CANbus voltage. In short, there are two points. One is not to exceed the maximum limit, and the other is not to insert the wrong position. As a tool to detect and upgrade can bus or to convert can bus data, all kinds of can analyzers and can gateways are necessary tools to maintain the normal operation of CAN bus. We must keep it in good working condition to prevent it from being out of hand when we need to use it, which is very embarrassing.