Rs-232C Communication - Hitachi CP-X980W Service Manual

13. 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.
D-sub 15-pin shrink
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_hige
CRC_low : Lower byte of CRC flag for command data.
CRC_high : Upper byte of CRC flag for command data.
3 Command data
Action
1
2
4
5
6
82
control terminal
5 4 3 2 1
10 9 8 7 6
15 14 13 12 11
byte_0 byte_1
Action
low high
Classification
SET
GET
INCREMENT
DECREMENT
EXECUTE
Projector Computer
1 1
CD
2 2
RD
3 3
TD
4 4 DTR
5 5 GND
6 6
SELO DSR
RTS 7 7
RTS
8 8 DTS
9 9 RI
GND 10
11
12
RD 13
TD 14
15
Command data chart
byte_2 byte_3 byte_4
Type
low high
Action (byte_0 - 1)
Change setting to desired value.
Read projector internal setup value.
Increment setup value by 1.
Decrement setup value by 1.
Run a command.
RS-232C terminal
D-sub 9-pin
1 2 3 4 5
6 7 8 9
byte_5
Setting code
low high
Content