When the “Fire” button is clicked for an RXREG row, a packet of characters is sent to the UART. The content of this message is specified in the “Comments” column. There are two ways to specify the message as shown in this illustration. “Direct Message” in the Action cell will send the exact text string in the “Comments” column. Hex numbers can also be used here. If the UART is not turned on or is full, the pending characters will be lost. Predefined messages can be sent to the UART register with the “File Message” action. Select this and click on the “Comments” cell to specify the message file. For more information on the format, please consult the help file “Message-Base Data File Description” in MPLAB.