The XLC4 commands are transferred in a command message of a uniform string structure:

Start	Address	Space	Command	End
STX	“#”, HexChar	Blank	String	ETX
0x02	0x23, HexChar	0x20		0x03
Start of command	Optional, for use with RS485 port			End of command
	Allowed characters: 0, 1, 2, 3, 4, 5, 6, 7, 8, 9, A, B, C, D, F

The message string is enclosed by STX as start character and ETX as end character. If the controller does not receive STX, the message will be ignored. If the controller does not receive ETX, no response will be sent.
Handle this issue using a time-out.

The command string has the following structure:

CommandID

Space

ParameterList

2 or 3 uppercase characters

0x20

List of decimal or hexadecimal numbers
Alphanumeric characters

See at each command

As separator from PrarmeterList

More than one parameters are separated by a blank character (Space) or by comma (“,”)

comma is used to separate numbers

Each command message sent to the XLC4 is acknowledged by a response message of the following structure:

ResponseMessage = STX , Response , ETX

Response	=	ResponseID , [ValueList]
ValueList	=	Space, Value, {“,” , Value}
Value	=	decimal number \| hexadecimal number \| single character \| string

Send command sequences to the XLC4 control unit