Rs-232C Commands - ViewSonic PJ452 - LCD XGA Projector-4.9LBS Service Manual

10. RS-232C communication
9 8 7 6
4 3 2
5
CONTROL port
of the projector
Connecting the cable
(1) Turn off the projector and the computer power supplies.
(2) Connect the CONTROL port of the projector with a RS-232C port of the computer by a RS-232C
cable(Cross). Use the cable that fulfills the specification shown in the previous page.
(3) Turn on the computer power supply and after the computer has started up, turn on the projector power
supply.
Communications setting
19200 bps, 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
Action
low high
Action (byte_0 - 1)
Action
1 Set
2 Get
4 Increment
5 Decrement
6 Execute
ViewSonic Corporation
1
RD (2)
TD (3)
GND (5)
RTS (7)
CTS (8)
byte_2 byte_3
Type
low high
Classification
RS-232C
cable(Cross)
- (1) (1) CD
(2) RD
(3) TD
- (4) (4) DTR
(5) GND
- (6) (6) DSR
(7) RTS
(8) DTS
- (9) (9) RI
byte_4
Setting code
low
Change setting to desired value.
Read projector internal setup value.
Increment setup value by 1.
Decrement setup value by 1.
Run a command.
43
1 2
6
7
RS-232C port
of a computer
byte_5
high
Content
Confidential - Do Not Copy
3 4 5
8 9
PJ452