Command Return Codes, Transaction Examples

5 COMMAND RETURN CODES

The Serial protocol returns an acknowledgment (“return code”) for every packet sent. If

the host sends a packet, then the projector acknowledge the receipt of this packet. The return codes are detailed in the table below.

Command Return Code Name	Return Code Value	Description
ACK	0x06	Packet acknowledged – no errors. Normal
		response when receiving
NAK	0x15	Packet not acknowledged – some error occurred in
		receiving this packet. Usually
		Indicates a CRC error.
ERR	0x1C 0xXXXX	Packet was received OK, but an error occurred
		when executing the command contained in the
		Packet. The two bytes following the 0x1C
		(0xXXXX) are the error code
VAL	0x1D 0xXX 0xYY	Packet value returned. This return code will be
		sent in response to a Operation packet of type
		OPERATION_GET. The first byte after 0x1D
		(0xXX), is the least-byte of the returned value. The
		0xYY is the most significant-byte of the returned
		value.
STRING	Strings 0x06	ASCII Strings and at last ACK

Table 8

Example 1: Set

Host:Projector Operation Set Packet =>

<= ACK

Example 2: Get

Operation Get Packet =>

<= VAL

VAL=0x1D 0x00 0x03 means that 0x0300 is returned

Example 3: Hex sequence for Set Brightness to 70% => 0.7*255 = 178 = 0xB2

Host:

Magic number Body size	CRC	Op.type Function	Value
7byte Message Head		6byte Message Body

Projector:

0x06

Example 4: Hex sequence for power on (with CRC deactivated)

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