3M SC400 Serial Resistive, Справочное руководство

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3M Touch Systems Proprietary Information
CHAPTER 2
SC400 Controller Communications
This chapter discusses the fundamentals of communicating with the SC400 controller.
The firmware commands, which are usually issued by a driver or utility program on the
host system, control the operation of the touch screen controller, however developers can
enter these commands directly. This chapter:
•
Describes the controller default settings.
•
Lists the recommended firmware commands.
•
Describes how to use each of these commands.
•
References additional commands developers may need to use.
The description of each command includes the command syntax, the default value, how
the command works, and the expected response from the controller.
Controller Default Settings
Communication Parameters
The SC400 controller communication parameters are N81 (no parity, 8 data bits, and 1
stop bit) at 9600 baud.
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 SC400 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 Touch Systems touch screen controllers.
•
It 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.
Refer to the Format Tablet command in the firmware reference section.