ESC/VP Level 6 Serial Communication Manual (Abridged Edition)
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. |
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bytes. |
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| * Command layout is BigEndian. |
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(1) STX | (2) Size | (3) Attribute | (4) FromTo | (5) Group | (6) Item | (7) Parameter | (8) Check Sum |
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(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
---> 0x0009
Example) To check the power status over a serial connection
1D 000x 02 01 00 03 01 CS
---> 0x0008
(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 | Caption |
Set | 0x01 | Sets, reports and indicates values. |
Get | 0x02 | Gets the current value. |
Initialize | 0x03 | Initializes a value. |
Package | 0x05 | Command which combines the attributes of setting, reporting, indicating and requesting. |
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Table 5-2. Attribute of the Reply command
Attribute | Attribute code | Caption |
Return Packet for setting (OK) | 0x81 | Indicates that the set command received was analyzed correctly. |
Return Packet for setting (NG) | 0xC1 | Indicates that the set command received was not analyzed correctly. |
Return Packet for getting (OK) | 0x82 | Indicates that the get command received was analyzed correctly. |
Return Packet for getting (NG) | 0xC2 | Indicates that the get command received was not analyzed correctly. |
Return Packet for initializing (OK) | 0x83 | Indicates that the initialize command received was analyzed correctly. |
Return Packet for initializing (NG) | 0xC3 | Indicates that the initialize command received was not analyzed correctly. |
Response to package (OK) | 0x85 | Indicates that the combined attribute command received has been parsed correctly. |
Response to package (not OK) | 0xC5 | Indicates that the combined attribute command received has not been parsed cor- |
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Alert response to commands | 0x8F | Indicates that the command received contained an error and could not be parsed cor- |
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