After successfully testing two channels for sending and receiving data, it was discovered that the target bus or device could not be accessed to read the data.

Solution: The mutual transceiver test between the two channels was normal, indicating that the debugger software and hardware are functioning properly. Therefore, there is no need to suspect any issues with the debugger. To resolve the issue, the following items should be checked one by one.

①CAN is a differential level, wiring only CANH, CANL two wires, to ensure that the debugger and bus wiring is correct: CANH to CAN high, CANL to CAN low. (CANalyst-II Analyser Supreme Edition has one more S terminal for shielded wire wiring and lightning grounding, which is an auxiliary wiring.)

②Ensure that two 120-ohm terminating resistors are present across the bus when the debugger is connected to it.

③Ensure that the relay function is switched off as described earlier.

④Ensure that the debugging software is in its factory state. If it is not, delete the configuration file and restore the factory settings using the previously mentioned method.

⑤To start the device with the software in the factory state, configure the baud rate in the pop-up configuration dialogue box by selecting it directly from the baud rate drop-down list.   It is recommended to configure the baud rate when starting the device and not to change the default values of the other parameters. Avoid entering the parameter setting to configure the baud rate under normal circumstances.

⑥Ensure that the device is sending a signal by using an oscilloscope to detect the voltage between the CAN bus high and low lines. Connect the oscilloscope probe to CAN high and the oscilloscope ground to CAN low. Verify that there is a waveform and that the level is normal.

⑦To ensure proper functionality of standard CAN devices, it is important to confirm that the actual device baud rate matches.

The baud rate configured by the debugger. This can be achieved by directly configuring the corresponding value or by using an oscilloscope to test the baud rate value. Finally, the text should be free from grammatical errors, spelling mistakes, and punctuation errors, and all non-essential fillers should be removed. This can be achieved by directly configuring the corresponding value or by using an oscilloscope to test the baud rate value. Additionally, it is important to introduce and use specific term definitions consistently throughout the document and adhere to specific language standards, where applicable.

During the development stage of the CAN device, such as debugging development boards or early devices, it is crucial to follow a logical sequence and maintain a formal tone while using active voice predominantly for clearer, more direct communication. Firstly, check that the hardware is functioning correctly by verifying the waveform output and ensuring that the signal level is normal. Secondly, confirm that the actual baud rate matches the set value. It is important to note that different chips may have varying methods for setting the baud rate. If the baud rate does not match the set value, refer to the chip instructions for reconfiguration.

To measure the baud rate value using an oscilloscope, send any data from the device and observe the alternating 10 or 01 ID and data.   The figure below shows that the square wave frequency is 5kHz, corresponding to a baud rate of 10K. The differential level voltage is approximately 2V, slightly higher than normal.