5. COMMAND STRUCTURE
• ECommands are expressed as hexadecimal codes.
• All commands start with an ID code and end with a checksum.
When an ESC/VP command which is sent from the computer is received by the projector, a reply is returned.
However, the replies which are returned by the projector only indicate whether the initial command was received by the projector,
and do not indicate whether the command was executed or not.
Acquisition commands are sent in order to check the execution of a command.
In addition, if the next command is sent before the reply to a previous command has been received from the projector, it may
result in a communication error.
The command structure is shown below.
bytes.
(1) STX
(2) Size
(1) STX
: 0x1D (1 byte)
(2) Size
: Size of a command packet (Specifies a number of the data from 1D to CS) (2 bytes)
Example) To turn the power on over a serial connection
1D 000x 01 01 00 03 01 CS
Example) To check the power status over a serial connection
1D 000x 02 01 00 03
(3) Attribute
: Indicates attributes such as apply command/reply command, OK/Not OK, etc. (1 byte)
The attribute codes are shown below.
Table 5-1. Attribute of the Apply command
Attribute
Attribute code
Set
0x01
Get
0x02
Initialize
0x03
Package
0x05
Table 5-2. Attribute of the Reply command
Attribute
Return Packet for setting (OK)
Return Packet for setting (NG)
Return Packet for getting (OK)
Return Packet for getting (NG)
Return Packet for initializing (OK)
Return Packet for initializing (NG)
Response to package (OK)
Response to package (not OK)
Alert response to commands
ESC/VP Level 6 Serial Communication Manual (Abridged Edition)
(3) Attribute
(4) FromTo
---> 0x0009
01
CS
---> 0x0008
Sets, reports and indicates values.
Gets the current value.
Initializes a value.
Command which combines the attributes of setting, reporting, indicating and requesting.
Attribute code
0x81
Indicates that the set command received was analyzed correctly.
0xC1
Indicates that the set command received was not analyzed correctly.
0x82
Indicates that the get command received was analyzed correctly.
0xC2
Indicates that the get command received was not analyzed correctly.
0x83
Indicates that the initialize command received was analyzed correctly.
0xC3
Indicates that the initialize command received was not analyzed correctly.
0x85
Indicates that the combined attribute command received has been parsed correctly.
Indicates that the combined attribute command received has not been parsed cor-
0xC5
rectly.
Indicates that the command received contained an error and could not be parsed cor-
0x8F
rectly.
* Command layout is BigEndian.
(5) Group
(6) Item
Caption
Caption
5 of 20
* The maximum length for a command is 1024
(7) Parameter
(8) Check Sum
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