CAN Hacker: RTR Data Length 0?

Hello,

I've been playing around with the CAN Hacker recently and I think it's really good. However, I've noticed something. When you want to send an RTR message and click the 'RTR' button, the data length is set to zero.

I find that quite problematic. An RTR message must have a non-zero data length, because it's supposed to transmit as many data packets as were requested in the RTR message. While you do get a response from the other side using the CAN-Hacker, it won't contain any data packets because the CAN-Hacker sends the RTR message with a data length of zero.

Therefore, the RTR mode is unfortunately unusable. Is there anything else we can adjust?

Best regards,
Runny.

Hello,

Therefore, the RTR mode is unfortunately unusable. Is there anything else we can adjust?

Best regards,
Runny

...and what happens if you modify the DLC after clicking on the 'RTR' button?
At least, that's what the CAN hacker allows. But I don't know exactly what is actually being sent at the moment.

Bye.
Andi.

Hello,

When you set the Data Length to, for example, 6 after clicking 'RTR,' the controller doesn't respond at all; it doesn't receive any message. It appears that the CAN-Hacker isn't sending anything, or nothing that can be interpreted as a CAN message. While the transmit counter in the CAN-Hacker increases, nothing arrives at the receiver.

Therefore, it appears that the correct Remote Transmission Request (RTR) functionality is not implemented or working properly in the CAN-Hacker.

Best regards,
Runny.

Hello,

I don't actually use the CAN-Hacker (and only rarely RTR) - but:

There are various systems, whether they exist in the automotive sector or not, that respond to remote frames with a data frame containing data fields of a fixed length, regardless of what the DLC (Data Length Code) in the remote frame indicates.
It's understandable, because what should the remote device do when it receives a request to "send me 5," but the requested message contains 8 bytes of data?
So, I can imagine that the CAN hacker might work in a similar way with some systems/cars.


Best regards,
Ingo