Compaq 99875320-5 - Manual (Page 23)

Section 4. USB Communications
data. The HID specification requires that Reports be fixed in length. Command data may vary
in length. Therefore, the Report should be filled with zeros after the valid data.
RESULT CODE
This one-byte field contains the value of the result code. There are two types of result codes:
generic result codes and command-specific result codes. Generic result codes always have the
most significant bit set to zero. Generic result codes have the same meaning for all commands
and can be used by any command. Command-specific result codes always have the most
significant bit set to one. Command-specific result codes are defined by the command that uses
them. The same code can have different meanings for different commands. Command-specific
result codes are defined in the documentation for the command that uses them. Generic result
codes are defined in the following table.
Value
(Hex)
Result Code Description
00 SUCCESS The command completed successfully.
01 FAILURE The command failed.
02 BAD_PARAMETER The command failed due to a bad
parameter or command syntax error.
GET AND SET PROPERTY COMMANDS
The Get Property command gets a property from the device. The Get Property command
number is 0x00.
The Set Property command sets a property in the device. The Set Property command number
is 0x01.
The Get and Set Property command data fields for the requests and responses are structured as
follows:
Get Property Request Data:
Data Offset Value
0 Property ID
Get Property Response Data:
Data Offset Value
0 – n Property Value
Set Property Request Data:
Data Offset Value
0 Property ID
1 – n Property Value
Set Property Response Data:
None
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