Connection to the control signal terminal (continued)
Requesting projector status
(1)Send the request code ‘20H’ + ‘yyH’ from the computer to the projector.
(2)The projector returns the response code ‘1xH’ + ‘yyH’ +data to the computer.
Changing the projector settings
(1)Send the setting code ‘3xH’ + ‘yyH’ +data 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 ‘1xH’ + ‘yyH’ +data to the computer.
Caution The response data in (3) above need not match the setting data in (1).
For example, when the projector cannot set the setting data in (1), the projector may set the closest value. That value will be used as the response data in (3). Or else the projector will return the error code ‘0xH’ + ‘yyH’ +data.
Using the projector default settings
(1)The computer sends the default setting code ‘40H’ + ‘yyH’ to the projector.
(2)The projector changes the specified setting to the default value.
(3)The projector returns the default value with the response code ‘1xH’ + ‘yyH’ =data.
When a command sent by the projector cannot be understood by the computer
(1)The computer sends the command code ‘3xH’ , ‘4xH’ or ‘4xH’ + ‘yyH’ +data to the projector.
(2)When the command sent by the projector cannot be understood, the error command ‘00H’ + ‘yyH’ is returned by the computer.
When data sent by the projector cannot be understood
(1)The computer sends the command code ‘3xH’ , ‘4xH’ or ‘4xH’ + ‘yyH’ +data to the projector.
(2)When the command sent by the projector cannot be understood, the error code ‘0xH’ +‘yyH’ +data is returned.
When the data length is greater than indicated by the data length code, the projector will 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 projector.
When a frame error occurs
Repeats 10 times per second until there is some sort of response to the error code 70H + 70H.
When the interval between bytes in one command is 500ms or greater
When a command or data is not sent within 500ms after the command code ‘2xH’ , ‘3xH’ or ‘4xH’ is sent by the computer, the error command ‘70H’ +‘70H’ will be returned as soon as the 500ms elapses. After this, if there is no response within 1 sec., a frame error will occur.
Caution • Operation cannot be guaranteed when the projector receives an undefined command or data.
• Provide an interval of at least 40ms between the response code and any other code.
30