Why do not I receive COMMAND_LONG

Hi, I am trying to receive COMMAND_LONG message on UART4 port, but I only can receive COMMAND_ACK messages. I searched for any information about the command protocol, but find nothing, which could help me. Does anybody know, how to do it?

Thanks

Hello! I have a similar problem. Did you manage to get a solution? How did you define your packing message?