Method for analyzing and triggering controller area network (CAN) bus

Abstract

The invention discloses a method for analyzing and triggering a controller area network (CAN) bus, which can provide a triggering and decoding function of a CAN bus for a measuring instrument. The method comprises the following steps of: converting a CAN bus signal to be measured into a digital signal through an analog-to-digital converter; generating, by a sampling clock generator, sampling clock of corresponding frequency to a snapshot module to snapshot the digital signal according to baud rate set by a user; converting, by a digital comparator, into 0 / 1 value and then transmitting to a decoding module to extract frame information; transmitting to a comparative trigger module to compare with a trigger condition set by the user; and if the trigger condition is met, generating a trigger signal to an acquisition control module to control acquisition and storage of the signal after snapshot. The frame information output by the decoding module can be transmitted to a subsequent processing module together with acquired and stored waveform information so as to be used for further analysis processing. By adopting the method, the acquisition of an interesting CAN bus event of the measuring instrument is facilitated, interruption of the CAN bus information of the user is facilitated, and debugging efficiency of the CAN bus is increased.

Description

technical field [0001] The invention relates to a method for analyzing and triggering a controller local area network bus signal in a measuring instrument, in particular to an analysis and triggering method for a controller local area network bus signal in a digital oscilloscope. Background technique [0002] The Controller Area Network (CAN) bus is a layered serial data communication protocol specially developed by Bosch in the 1980s to serve as a communication bus between devices in an electrically noisy environment. In the CAN bus, information such as frame header, identifier (address), data length code, data, CRC and frame tail, and a small amount of other control bits are transmitted serially on one wire. The traditional trigger method of measuring instruments (such as edge trigger) cannot effectively capture bus information. Therefore, it is necessary to equip the measuring instrument with a special CAN bus signal analysis and trigger method, analyze and extract the f...

AI Technical Summary

Problems solved by technology

In the CAN bus, information such as frame header, identifier (address), data length code, data, CRC and frame tail, and a small amount of other control bits are transmitted serially on one wire. The traditional trigger method of measuring instruments (such as Edge trigger) cannot effectively capture bus information

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