JVC Model DLA-HX1E manual  RS-232C external control, Communication Specifications, Command Format

Specifications

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	9600 bps/19200 bps
Data length	8 bits
Parity	None
Stop bit	1 bit
Flow control	None

2.Command Format

2-1 Command data format

When sending a control command to the projector, use the following data format.

Header

Header

ID

SP

CR

ID SP Command [ SP Parameter [ CR

:Designates the head of data and the data type.

:! (21h): Assigns command to the projector.

:? (3Fh): Query to the projector. (Asking command)

: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)

* [ ] is not necessary for Asking command.

2-2 Response data format

Upon executing a control command it has received, the projector sends back the following response data to the computer:

Header ID SP

Header

ID

SP

Normal Termination Status

CR

Normal Termination Status [ SP Parameter [ CR

: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)

:0 (30h)

:Designates the terminal of the data. (0Dh)

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	Hex.	Meaning
0	30	OFF
1	31	ON

59