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3M™ MicroTouch™ Controller RX142 Reference Guide
3M Touch Systems, Inc. Proprietary Information
The low order bits (X3 – X0 and Y3 – Y0) are not significant in a 1024 by 1024 sensor
because data can fluctuate with each touch, and therefore may not be completely
accurate.
Table 4 Data Sequence
MSB
Bits
LSB
Data Sequence 7
6
5
4
3
2
1
0
S Byte
1 1
S6 S5 S4 S3 S2 S1 S0
X Byte
2 0
X6 X5 X4 X3 X2 X1 X0
X
Byte 3
0
X13 X12 X11 X10 X9 X8 X7
Y Byte
4 0
Y6 Y5 Y4 Y3 Y2 Y1 Y0
Y
Byte 5
0
Y13 Y12 Y11 Y10 Y9 Y8 Y7
Table 5 defines the status bits (Byte 1) for the Format Tablet data.
Table 5 Format Tablet Status Bits
Bit
Description
Values
S0 – S5 Reserved
—
S6
Proximity (touch state) 1 = Sensor is being touched (a touchdown or a continued touch).
0 = Sensor 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.
Get Controller Number
Syntax:
<SOH>
Q002
<CR>
Response:
<SOH>
XXXXXXXX
<CR> Where each X is a hexadecimal digit, most significant digit
first.
Description:
This command is used to get a controller number for applications use. The controller does
not use this value. This is useful for identifying individual controllers in a multiple
controller system.
Mode Stream
Syntax:
<SOH>
MS
<CR>
Response:
<SOH>
0
<CR> Positive
response.
The controller will respond with ACK for compatibility with older controllers. This
format is the only format supported by this controller.
Description:
Sends a continuous stream of X/Y coordinate data when you touch the sensor. The
controller continues to send data as long as you touch the sensor. The controller sends the
data even if the touch is stationary and unchanging.
