JVC DLA-SX21U Instructions Manual page 55

RS-232C external control
By connecting a computer to the projector with a RS-232C cross cable (D-sub 9 pins), you can control the projector with the
computer. The commands to control the projector and the response data format against the received commands are explained
here.
For details, please consult the authorized dealer where you purchased your projector.
1. Communication Specifications
The communication specifications are as follows.
Baud rate
Data length
Parity
Stop bit
Flow control
2. Command Format
2-1 Command data format
When sending a control command to the projector, use the following data format.
Header ID
Header : Designates the head of data and the data type.
: '!' (21h): Assigns command to the projector
: '?' (3Fh): Query to the projector (Asking command)
ID : '1': The identification number of the projector. (Manufacturer set value '1')
SP : Designates the delimiter for ID, Command, and Parameter. (20h)
CR : Designates the terminal of the data. (0Dh)
* [ ] is not necessary for Asking command.
2-2 Response data format
Upon executing the received control command, the projector sends back the following response data to the computer.
Header ID
Header
ID
SP
Normal Termination Status : '0' (30h)
CR
2-3 Parameters used for the data format
The following three kinds of parameters are used for control commands and response data.
1) Numeric value
2) ON/OFF
3) Special parameters
Each parameter is as follows:
1) Numeric value
A 2-byte hexadecimal value (sign included) is represented by a set of 4 digit (4 bytes) characters.
Designated range: '8000' to '7FFF'.
2) ON/OFF
Shows the status (ON/OFF) of the projector, such as POWER and HIDE.
Character
'0'
'1'
9600bps/19200bps
8 bits
None
1 bit
None
[
SP Command SP
SP Normal Termination Status
: Designates the head of data.
: '@' (40h): Fetches data from the projector.
: '1': The identification number of the projector. (Manufacturer set value"1")
: Designates the delimiter for ID, Command, and Parameter. (20h)
: Designates the terminal of the data. (0Dh)
Hex. Meaning
30 OFF
31 ON
[
Parameter
CR
[
Parameter
SP
Specifications
[
CR
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