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<!DOCTYPE concept

  PUBLIC "-//OASIS//DTD DITA Concept//EN" "concept.dtd">

<concept id="GUID-8798F896-E0CB-4B9B-8F88-3C8B58574213" xml:lang="en"><title>The

Physical Channel</title><shortdesc>This document describes how a logical device communicates with

a physical device over a physical channel.</shortdesc><prolog><metadata><keywords/></metadata></prolog><conbody>

<section id="GUID-A759AA8D-945A-4150-822A-C22DFAE8F5C9">           <p>The

physical channel defines the interface between the logical device and the

physical device. Typically, this interface is different for each device family

and, therefore, the device driver framework does not require a particular

type of interface. The only requirement is that the physical channel class

is derived from <xref href="GUID-4FCB6127-84F3-38F6-8AD2-FC3B94D67DA3.dita"><apiname>DBase</apiname></xref>. It is up to the driver writer to

define the physical channel class. </p> <fig id="GUID-8C470617-1743-546F-A0A4-A20B1480539D">

<title>                 Device driver physical channel classes           

   </title>

<image href="GUID-F8A32666-5003-5B14-A700-C6E6388D2D38_d0e291470_href.png" placement="inline"/>

</fig>     </section>