Grundig CP-731i RS-232C communication, Communications setting, Protocol, Header, Command data

TECHNICAL (continued)

RS-232C communication

(1)Turn off the projector and computer power supplies and connect with the RS-232C cable.

(2)Turn on the computer power supply and, after the computer has started up, turn on the projector power supply.

	Projector
Control jack		2
D-sub 15-pin shrink jack	SELORTS109345678
1510149138127116	GND	2
	RDT	43
		15

Computer		RS-232C jack
2	RD	D-sub 9-pin
3456789	TDGNDDRITRSRTS	162738495

Communications setting

19200bps, 8N1

1 Protocol

Consist of header (7 bytes) + command data (6 bytes).

2 Header

BE + EF + 03 + 06 + 00 + CRC_low + CRC_high

CRC_low : Lower byte of CRC flag for command data.

CRC_high : Upper byte of CRC flag for command data.

3 Command data

Command data chart

byte_0	byte_1	byte_2		byte_3	byte_4	byte_5
Action			Type		Setting code
low	high	low		high	low	high

		Action (byte_0 - 1)
Action	Classification		Content
1	SET		Change setting to desired value.
2	GET		Read projector internal setup value.
4	INCREMENT		Increment setup value by 1.
5	DECREMENT		Decrement setup value by 1.
6	EXECUTE		Run a command.

TECHNICAL - 6