Test Case: Command_Ctrl
Description: Assure that commands given are carried out with response.

1. Open a TTY connection with 115200 8N1.
2. Connect a USB host to the DUT with a 3.1 cable.
3A. Enter a test command opcode terminated with a CR/LF.
3B. Compare with the well known response text.

Command Opcode  :  Response
--------------     --------
ASDFUIOP  :  Command unknown
HELP  :  Enter a command
MENU  :  HELP
         MENU
         DUMP