EX II 3000SP Controller Communications
25
3M Touch Systems Proprietary Information
No Response
<SOH>
2
<CR>
Indicates that the user did not touch the target long enough to provide an
accurate calibration point.
Calibrate Raw
Syntax:
<SOH>
CR
<CR>
Description:
Allows the collection of raw (signed) X and Y coordinates prior to the
normal scaling, linearization, and filtering processes. The controller sends
the coordinates whenever a touch is detected and continues to send a stream
of data as long as a finger remains in contact with the touch screen.
The Calibrate Raw data is a 5-byte packet that includes 1 status byte and 4
bytes of binary X/Y coordinate data. Each X/Y coordinate includes 10
binary bits and 1 sign bit. The 10 bits represent coordinates within a range
of -1024 to +1023.
To use the Calibrate Raw command, the controller and host system must be
in an 8-bit data communication mode. The Calibrate Raw command returns
a negative response if the controller is not using an 8-bit communication
mode.
To end Calibrate Raw mode, issue a Reset command. 3M Touch Systems
uses the Calibrate Raw command during manufacturing and testing, and
recommends you only use this command for diagnostics when you want raw
data.
Response:
<SOH>
0
<CR> Positive response
After the controller is in Calibrate Raw mode, touching the screen causes
the controller to return a response in the following format:
SXxYy
where:
S
= Status byte, first byte of data. Refer to Table 4.
Xx
= X (horizontal) coordinate data; second and third bytes of data
Yy
= Y (vertical) coordinate data; fourth and fifth bytes of data.
Table 4 Data Sequence
MSB*
Bits
LSB*
Data Sequence
7
6
5
4
3
2
1
0
S- Byte 1
1
S6
Reserved
X- Byte 2
0
X3
X2
X1
X0
Reserved
x- Byte 3
0
Xs**
X9
X8
X7
X6
X5
X4
Y- Byte 4
0
Y3
Y2
Y1
Y0
Reserved
y- Byte 5
0
Ys**
Y9
Y8
Y7
Y6
Y5
Y4
*
MSB = Most Significant Bit, LSB = Least Significant Bit
**
s = sign bit
