16-bit Representation: Explained & Examples

Hello!

I've only recently started working with the CAN bus.

I used KCANMonitor to log the process of reading an EEPROM via OBD.

Unfortunately, it's only displayed with 8 bits. Is there a way to switch it to 16 bits?

Is it somehow possible to save the read data as a BIN file? The EEPROM ranges from offset 00000000 to 00001FF0, which is 8192 bytes minus 16 bytes.

Hi,

The CAN log from the read-out process doesn't actually represent the "content" of the EEPROM; rather, you see the CAN messages that request information from the EEPROM and the corresponding responses that contain the EEPROM data.

Quote:

Unfortunately, it is only displayed with 8 bits; is there a way to switch it to 16 bits?

A bit pointless... from two 8-bit values, one should be able to create a 16-bit value in the desired byte order simply by looking at them.
Example: 0x12 0x34 can be either 0x1234 or 0x3412, depending on the byte order used.

What protocol is used to query the data? Is it KWP2000 over CAN (ISO 11898, ISO 15765-2)?

Okay, I'm ready. Please provide the German text you want me to translate into English. I will only provide the translation.
I would check the protocol IDs 0x21, 0x22, 0x23, etc., and see if any of them appear in the CAN log.

Unfortunately, the KWP2000 or UDS specifications with details on the protocol IDs are not freely available; however, I am sure that some information can be found online.

Best regards, Rainer.

Okay, Rainer, I'll take a look at it right away.

It is a VW UDS control unit.

Data is output to address 0X77E.

chriskross wrote:

Thank you, Rainer, I will take a look at it right away. It is a VW UDS control unit. Data is output to 0x77E

.
The CAN ID used has nothing to do with the protocol ID.

Best regards, Rainer.
Sure, you could certainly include a portion of the log here (the beginning plus about 30 lines would probably be enough), and then we can see what's happening.

chriskross wrote:

Thank you, Rainer, I will take a look at it right away. It is a VW UDS control unit. Data is output to 0X77E

.

Let me guess: an NEC 24c32 or 64 speedometer.

If you read out the EEPROM, you can search for specific parts of it within the CAN log!

Greetings.