3M EX II 3000SP 用户手册

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                 EX II 3000SP Controller Reference Guide

3M Touch Systems Proprietary Information

Table 5 describes the meaning of the bits in the status byte (Byte 1).

S0 – S5

Reserved

—

S6

Proximity
(touch state)

1 = Touch screen is being touched (a touchdown
or a continued touch).
0 = Touch screen is not being touched (a touch
liftoff or inactive).
When the proximity bit changes from 1 to 0 (touch
liftoff), the controller outputs one final set of X/Y
coordinate data with the bit equal to 0 and the X/Y
coordinate data equal to the last touch point.

S7

Packet
synchronization

Always 1.

Syntax: 

<SOH>FO<CR>

Description: 

The controller is set to only respond to finger touches and disable the
TouchPen.

Response: 

<SOH>0<CR> Positive response

Syntax: 

<SOH>FR<CR>

Description:

Returns the signal level (amount of touch) of each of the four touch screen
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 6 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 7 for I/Q Corner
Components.