I am using an AXC 3152 in my project, with a AXL F IF CAN 1H, to communicate with a charge controller. I used the PLCnext CAN function blocks (CAN_COM and CAN_J1939 read/write).
I am able to read data from the controller into the PLC, but the charge controller does go into error for the following reason:
‚No acknowledgment is received for the CAN messages the charge controller sends over the bus by any of the nodes. Therefore, these messages will remain in the buffer until it overflows.‘
How can I make sure the PLC is acknowledging the messages it has received?
Hello ShaheerNawaz22,
Regarding the charge controller: I’m not entirely familiar with its specific implementation, but as far as I understand, it behaves like a standard J1939 device on the CAN bus.
In general CAN messages under the J1939 protocol are typically not acknowledged by receiving nodes in the sense of sending a confirmation message back. It seems that this charge controller might have some kind of application-level requirement for an acknowledgment, which would be specific to that device.
I’d recommend checking the device’s manual or documentation to understand how it expects to receive acknowledgments. If it requires a particular response message after receiving data, you can use the read function block in PLCnext to detect incoming messages and then manually construct and send the appropriate acknowledgment message back onto the bus.
Please note that our function blocks do not currently include a built-in feature to automatically send acknowledgments, that logic would need to be implemented in your application code if required.
I understand this might not be the answer you were hoping for, but I hope it helps you move forward in the right direction.
Best Regards,
Jorne