3M MP8747, MP8746 RS-232 Communication, Communications Setting 19200bps, 8N1 Protocol, Header

Technical Appendix

RS-232 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	Computer
						1	1	CD
CONTROL Terminal						2	2	RD
						3	3	TD	RS-232C jack
						4	4	DTR
D-sub 15-pin shrink jack									D-sub 9-pin
						5	5	GND
5	4	3	2	1		SELO 6	6	DSR	1	2 3	4	5
						RTS 7	7	RTS
	10	9	8	7	6	8	8	DTS	6	7	8	9
15	14	13 12		11
						9	9	RI
						GND 10
						11
						12
						RD 13
						TD 14
						15

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

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

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.

36 3M™ Personal Projector MP8746/MP8747 © 3M IPC 2000