3M MicroTouch EX Series, Справочное руководство

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18 3M™ MicroTouch™ Controller EX Serial Reference Guide
3M Touch Systems, Inc. Proprietary Information – TSD-29087 Rev D
To optimize the performance of the 3M™ MicroTouch™ EX touch controller and
simplify the development of custom drivers, 3M Touch Systems recommends you use the
commands listed in this chapter for current development. Using these commands ensures
compatibility with all 3M™ MicroTouch™ controllers.
Controller Default Settings
Communication Parameters
The default operation of the EX serial controllers is N81 (no parity, 8 data bits, and 1
stop bits) at 9600 baud. Some EX1N2 controllers can be programmed to work with
even/odd parity, 7 data bits, and 1 or 2 stop bits.
Data Format
Data format refers to the type of packet the controller uses to send the X/Y touch
coordinates to the host system. Format Tablet is the default format for the 3M™
MicroTouch™ EX serial controller. In Format Tablet, the controller sends 5 bytes per
point and provides the most rapid response time to a touch.
•
Format Tablet is supported by all current 3M™ MicroTouch™ touch controllers.
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It is the standard for current 3M Touch Systems product development and is the
format used by all touch drivers written by 3M Touch Systems.
Refer to the Format Tablet command in the firmware reference section. Note that 3M
MicroTouch Software automatically sets communications parameters to N81.
Operating Mode
The operating mode specifies the conditions under which the controller sends the X/Y
touch coordinates (input data packet) to the host system.
Mode Stream is the default operating mode for the EX serial controller. In Mode Stream,
the controller sends a continuous stream of data packets when the sensor is touched. The
controller sends the data as long as a touch continues on the sensor.
Because Mode Stream sends touch data continually, it is the most versatile mode, and it
provides the best response time and overall feel.
3M Touch Systems recommends that the touch driver generate an interrupt as each
packet in the data stream arrives. Because touchdown and liftoff events are specially
coded, your software can generate mouse events that correspond to what the user is
doing. This enables instant feedback and prevents data loss.
Communicating with the Controller
This section provides information on sending firmware commands to the controller and
interpreting the responses that the controller returns.