EX II 3000SP Controller Communications

25

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

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