3M Touch Screen USB Resistive Controller SC500, Справочное руководство

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SC500 USB Controller Communications 19
3M Touch Systems Proprietary Information
Table 7. General Request Format
Offset Field Size Value Description
0 bmRequestType 1 d0100001 Characteristics of request (dir,type,receipt)
D7: Data transfer direction
0 = Host to device
1 = Device to host
D6…5 Type
0 = Standard
1 = Class (all commands are standard)
2 = Vendor
3 = Reserved
D4…0 Recipient
0 = Device
1 = Interface (all commands are interface)
2 = Endpoint
3 = Other
4….31 = Reserved
1 bRequest 1 0xXX Specific request (our command number)
2 wValue 2 0x03XX Used to specify command parameters.
03 = Feature
XX = Feature Report ID
4 wIndex 2 0 Must be 0 (zero)
6 wLength 2 0xXXXX Number of bytes to transfer, multiple of 8. Same
as Data Stage Bytes in Table 8.
HID Class Requests
The following table summarizes the available HID class requests.
Table 8. Hid Class Requests Summary
Some possible reasons for a command failure include:
•
The command was not formatted correctly.
•
The system parameters were not set up to allow command execution.
•
The controller does not support the command.
HID Report Command Name bmRequest
Type bRequest Feature
Report ID Report
Subtype Data
Stage
Bytes
Set Feature SetAsyncReport 0x21 0x09 0x03 0x05 8
Set Feature Calibrate 0x21 0x09 0x03 0x04 8
Get Feature GetStatus 0xA1 0x01 0x06 --- 8
Set Feature Reset 0x21 0x09 0x03 0x07 8
Set Feature Restore Defaults 0x21 0x09 0x03 0x08 8
Set Feature Set Controller Number 0x21 0x09 0x05 0x01 8
Get Feature Get Controller Number 0x21 0x09 0x03 0x02 8