3M Touch Screen Controller RX181, Справочное руководство

Страница: 18 / 31

18 3M™ MicroTouch™ Controller RX181 Reference Guide
3M Touch Systems, Inc. Proprietary Information
Table 6. Coordinate Data Report Touch Status Byte
Bit Status
0 0 = not touching, 1 = touching
1 0 = data invalid, 1 = data valid
2 Not used
3 Not used
USB Command Set
The USB command set is implemented by using HID Get Feature and Set Feature
commands. The various requests and reports are grouped together by report size under a
common feature ID.
The commands listed below are those that 3M Touch Systems currently use for
communications. 3M Touch Systems recommends that you use only these commands for
RX181 controller communications.
Sending Commands to the Controller
To send a command, the computer must construct a USB packet for sending to the
controller. The general packet format is described in Table 7. Any data appended
immediately after this data is referred to as the data stage of request.
If using Windows you may want to use the Set and Get Feature functions. The buffers are
the same except the first two fields. The bmRequest Type and bRequest fields are
omitted, thus making wValue the first field. For your convenience, each command is
labeled as either a “Set Feature” or “Get Feature” command.
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)