3M MicroTouch EX Series, Справочное руководство

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26 3M™ MicroTouch™ Controller EX Serial Reference Guide
3M Touch Systems, Inc. Proprietary Information – TSD-29087 Rev D
Description: Returns the signal level (amount of touch) of each of the four sensor corners in digital
format. The returned values are not corrected for stray values.
The Format Raw data is a 41-byte packet that includes 1 status byte and 40 bytes of
binary corner data. The first byte of each packet always has its high bit (Bit 7) set to
provide synchronization with the host system. Refer to Table 8 for General Packet
Formats. Each corner data is composed of a pair of 32-bit I and Q values, which are
delivered in 10 bytes.
I and Q are complex touch currents as measured in phase and 90 degrees out of phase
with the corner drive signal. Refer to Table 9 for I/Q Corner Components.
To use the Format Raw command, the controller and host system must be in an 8-bit data
communication mode. The Format Raw command returns a negative response if the
controller is not using an 8-bit communication mode.
To terminate Format Raw, issue a Reset command. The controller may return several
bytes of data between the time you issue a Reset command and the controller receives it.
You can either scan the data stream for the Reset acknowledgment, or you can ignore the
response to the first Reset command and then issue a second Reset after approximately
10 seconds has passed.
Use the Format Raw command for diagnostics. Use Format Tablet for standard sensor
operation.
Response: <SOH>0<CR> Positive response.
After the controller is in Format Raw mode, the controller returns a continuous response
in the following format:
<41-byte-packet><41-byte-packet>...<41-byte-packet>...
Table 8 General Packet Formats
Byte Bits 0 – 7
1 b0 – b6: Reserved
b7: Synchronization bit (Always 1)
2-6 I component of upper left (UL) corner
7-11 Q component of upper left (UL) corner
12-16 I component of upper right (UR) corner
17-21 Q component of upper right (UR) corner
22-26 I component of lower left (LL) corner
27-31 Q component of lower left (LL) corner
32-36 I component of lower right (LR) corner
37-41 Q component of lower right (LR) corner