How to check the quality of CAN channel by CAN bus detector
CAN bus detector is also called USBCAN analyzer. It is a common tool for CAN data inspection and maintenance. The can bus detector generally has a USB interface and one or two CAN bus interfaces (channels). The USB interface is naturally connected to a computer with detection software, while the CAN bus interface (channel) is connected to twisted pair Line, and then connect the target CAN device. Before using the CAN bus detector, we generally check its CAN bus channel to see if it can work normally, then, how should this check work be done? Today, we will briefly explain the common single-channel CAN bus tester and dual-channel CAN bus tester.
The first is the first type, a single-channel CAN bus detector, whose CAN channel detection requires the help of a CAN reflector. What is a CAN reflector? It is a device that immediately sends the data back intact after receiving the CAN data. It is enough to know this, and you don't need to go into the other details. Then, we return to the topic of detecting the CAN channel of a single-channel CAN bus detector. We first connect in the following order, that is, the USB interface of the computer with the detection software is connected to the USB interface of the CAN bus tester, and the CAN interface of the CAN bus tester is connected to the CAN reflector through a twisted pair. Yes, that's it. After the physical layer is connected correctly, we can let the CAN detection software send some data. This data is originally USB data. After passing through the CAN bus detector, it will be converted into CAN data. The CAN data will reach the CAN reflector board. Back to the CAN bus tester, and then converted to USB data again, displayed on the computer's test software, the data sent just now is exactly the same as the data received now, if this is the case, it means this single-channel CAN bus test There is no problem with the CAN channel of the instrument.
Then there is the second type, to detect whether the CAN channels (interfaces) of the dual-channel CAN bus detector can be used. Because the device itself has two CAN bus channels, it does not need to connect an additional reflector when testing, and only needs its own CAN1 channel and CAN2 channel to connect to each other. Of course, we must follow the basic working principle of CAN bus, so that CAN high connects to CAN high, and CAN low connects to CAN low, otherwise it will not be used. The USB interface of the device is still the USB interface of the computer, but at this time, the detection software on the computer must open two at the same time, one as the host computer of the CAN1 channel, and the other as the host computer of the CAN2 channel, and then send data to each other, You send me to receive or I send you to receive, the process is also the conversion of USB data into CAN data and then into USB data. If the data can be sent and received normally, it means that there is no problem with the CAN channel of your CAN bus tester, and you can use it with confidence.