3M EX II 3000SP Communicating with the Controller, Data Format, Operating Mode

18 EX II 3000SP Controller Reference Guide

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 format for the EX II 3000SP controller operating at 8 data bits only.

•Format Tablet uses only 5 bytes per point and provides a rapid response time.

•Format Tablet includes a status byte. The status byte contains information on whether the X/Y coordinate is generated from a touchdown, a touch continuation (when the finger is resting on the screen), or a touch liftoff.

•Format Tablet is supported by all current 3M Touch Systems touch screen controllers.

•Format Tablet is the standard for current 3M Touch Systems product development and is the format used by all touch screen drivers written by 3M Touch Systems.

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 II 3000SP controller. In Mode Stream, the controller sends a continuous stream of data packets when the screen 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 screen driver generate an event 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.

Communicating with the Controller

This section provides information on sending firmware commands to the controller and interpreting the responses that the controller returns.

The EX II 3000SP command set is compatible with the TP4+ controller and should not require modifications of existing software when replacing an older controller.

The commands listed in Table 3 are those that 3M Touch Systems currently uses for development. 3M Touch Systems recommends that you use only these commands for EX II 3000SP controller development.

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