Specifications

Chapter 6 - Touch Application Program Interface (TAPI) CARROLL TOUCH
6-2 Touch System Programmer’s Guide
Overview
The Touch Application Program Interface (TAPI) is a set of software
functions that lets an application communicate with a Carroll Touch
touch system using the Smart-Frame Protocol without interfacing
directly to the hardware. Using the TAPI interface protocol yields the
following benefits:
• An application that interfaces to a TAPI driver is independent of
the touch system hardware. Each touch system hardware
configuration has a TAPI driver, and all of these TAPI drivers
share a common interface (the TAPI interface). As a result, an
application that uses TAPI may be used with various touch system
hardware configurations without modification by simply loading
the appropriate TAPI driver.
• It is generally easier to write an application that uses TAPI
software interrupt calls to communicate with the touch system than
to write an application that interfaces directly to the touch system
hardware.
The TAPI interface does not include support for calibration or touch
coordinate scaling. These two functions must be performed by the
touch application itself, just as in touch applications that interface
directly to the touch system hardware.
There are three TAPI drivers:
• Software-based controller (SBC) driver.
• Hardware-based controller (HBC) driver.
• RS-232 controller driver.
TAPI driver is a generic term used to describe all three drivers. Each
TAPI driver is a terminate-and-stay-resident (TSR) program that makes
it possible to use the touch system via a software interrupt rather than
by directly accessing the touch system hardware.
The SBC driver must be loaded to use a touch system that uses the SBC.
The SBC is unable to use the Smart-Frame Protocol directly because
the SBC has no processor on board. Use of the HBC or RS-232 drivers
with touch systems that use the HBC or RS-232 controller is optional,
since the application may interface directly to the HBC or RS-232
controller using the Smart-Frame Protocol.
The TAPI drivers run on an IBM or IBM-compatible PC. Each TAPI
driver communicates with any Carroll Touch touch system or controller