Rs-232C Communication - Hitachi CP-SX635W Service Manual

1 2 3 4 5
6
7 8 9
CONTROL port RS-232C cable (Cross)
of the projector
- (1)
RD (2)
TD (3)
- (4)
GND (5)
- (6)
RTS (7)
CTS (8)
- (9)
Connecting the cable
Turn off the projector and the computer.
1.
Connect the CONTROL port of the projector with a RS-232C port of
2.
the computer by a RS-232C cable (cross). Use the cable that fulfills the
speci cation shown in the previous page.
Turn the computer on, and after the computer has started up turn the
3.
projector on.
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 ag for command data
CRC_high : Upper byte of CRC ag for command data
3. Command data
Command data chart
byte_0 byte_1 byte_2 byte_3
Action Type
low high low high
Action (byte_0 - 1)
Action Classi cation
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.
1 2 3 4 5
6
7 8 9
RS-232C port
of the computer
(1) CD
(2) RD
(3) TD
(4) DTR
(5) GND
(6) DSR
(7) RTS
(8) DTS
(9) RI
byte_4 byte_5
Setting code
low high
Content
RS-232C Communication (continued)
Requesting projector status (Get command)
(1) Send the request code Header + Command data ('02H'+'00H'+ type (2
bytes)+'00H' +'00H') from the computer to the projector.
(2) The projector returns the response code '1DH'+ data (2 bytes) to the computer.
Changing the projector settings (Set command)
(1) Send the setting code Header + Command data ('01H'+'00H'+ type (2 bytes) +
setting code (2 bytes)) from the computer to the projector.
(2) The projector changes the setting based on the above setting code.
(3) The projector returns the response code '06H' to the computer.
Using the projector default settings (Reset Command)
(1) The computer sends the default setting code Header + Command data
('06H'+'00H' + type (2 bytes) +'00H'+'00H') to the projector.
(2) The projector changes the speci ed setting to the default value.
(3) The projector returns the response code '06H' to the computer.
Increasing the projector setting value (Increment command)
(1) The computer sends the increment code Header + Command data
('04H'+'00H'+ type (2 bytes) +'00H'+'00H') to the projector.
(2) The projector in creases the setting value on the above setting code.
(3) The projector returns the response code '06H' to the computer.
Decreasing the projector setting value (Decrement command)
(1) The computer sends the decrement code Header + Command data
('05H'+'00H'+ type (2 bytes) +'00H' + '00H') to the projector.
(2) The projector decreases the setting value on the above setting code.
(3) The projector returns the response code '06H' to the computer.
When the projector cannot understand the received command
When the projector cannot understand the received command, the error code '15H'
is sent back to the computer.
Sometimes the projector cannot properly receive the command. In such a
case, the command is not executed and the error code '15H' is sent back to the
computer. If this error code is returned, send the same command again.
When the projector cannot execute the received command.
When the projector cannot execute the received command, the error code '1CH'
+ 'xxxxH' is sent back to the computer. When the data length is greater than
indicated by the data length code, the projector ignore the excess data code.
Conversely when the data length is shorter than indicated by the data length
code, an error code will be returned to the computer.
NOTE • Operation cannot be guaranteed when the projector receives an
unde ned command or data.
• Provide an interval of at least 40ms between the response code and any other code.
• The projector outputs test data when the power supply is switched ON, and when the
lamp is lit. Ignore this data.
• Commands are not accepted during warm-up.