Elo TouchSystems 1525L manual Overview, Part Number, Windows Version, Medium

SECTION 1. OVERVIEW

The MagTek Device (MTD) Drivers for Windows is a collection of individual drivers that support a number of MagTek products. These drivers provide a uniform application interface for controlling a wide range of MagTek devices. The drivers, combined with a device control language, solve many of the difficulties application developers face when attempting to control hardware devices. The difficulties mount when faced with the task of developing an application that supports an entire product line of devices.

Part Numbers for the MTD are as follows:

Part Number	Windows Version	Medium
30037385	All	CD
99510030	9X/ME	Internet* (MTD110-9x-ME)
99510031	NT	(MTD110-NT)
99510032	2000/XP	(MTD110-2K-XP)
*www.magtek.com

PROBLEMS WITH CONTROLLING DEVICES

The major problems with developing an application that supports an entire product line of devices are as follows:

•Each MagTek device has a unique set of commands. The commands usually perform similar functions on a particular class of devices but either differ in syntax or have small variations in their functionality. An application would have to implement a custom mechanism to control each device it supported–much like DOS applications had to do to support various printers.

•Most MagTek devices communicate via data streams, not packets. This means that an application receives data from the device one character at a time; it only receives partial command responses. It would be the application’s responsibility to collect the incoming data and parse it into individual responses.

•Responses from MagTek devices are inherently asynchronous. When an application sends a command that requires a response, the response from the device arrives (or worse, begins to arrive) long after the command is sent. The application would have to either poll the device until all of the response is collected or implement a callback mechanism to collect and receive it.

•Most MagTek devices maintain a communication protocol of some kind. In addition to this, the protocols differ between devices. For example, some devices frame responses with STX and ETX control characters and others simply use a CR or require a checksum in the frame. To deal with this, an application would have to recognize and implement all of the various protocols for the devices it supports.

87