<div class="content" name="Control_Call" uuid="002fc3a3-2ca2-492e-8463-aba8f3923e48"><p>Normally, communication is to the <a href="d361b24c-611e-46c5-9ac6-93cb6490a472#gt_7c0fcc4a-476a-4d3a-87c0-7a503c14ef05" data-linktype="relative-path">smart card</a> via the reader.
However, in some cases, the ability to communicate directly with the <a href="d361b24c-611e-46c5-9ac6-93cb6490a472#gt_5cddf14c-b925-4494-9b55-d2c8259f9ad0" data-linktype="relative-path">smart card reader</a> is
requested. The Control_Call structure provides the ability to talk to the
reader.</p><dl>
<dd>
<div><pre> typedef struct _Control_Call {
   REDIR_SCARDHANDLE hCard;
   unsigned long dwControlCode;
   [range(0,66560)] unsigned long cbInBufferSize;
   [unique] [size_is(cbInBufferSize)] const byte *pvInBuffer;
   long fpvOutBufferIsNULL;
   unsigned long cbOutBufferSize;
 } Control_Call;
</pre></div>
</dd></dl><p><b>hCard:</b>  A handle, as specified in
section <a href="b6276356-7c5f-4d3e-be92-a6c85e58d008" data-linktype="relative-path">2.2.1.2</a>.</p><p><b>dwControlCode:</b>  The control code for
the operation. These values are specific to the hardware <a href="d361b24c-611e-46c5-9ac6-93cb6490a472#gt_4712ded2-d927-4930-9450-29499f98cef4" data-linktype="relative-path">device</a>. This protocol MUST
NOT restrict or define any values for this control codes.</p><p><b>cbInBufferSize:</b>  The size in bytes
of the <b>pvInBuffer</b> field.</p><p><b>pvInBuffer:</b>  A buffer that contains
the data required to perform the operation. This field SHOULD be NULL if the <b>dwControlCode</b>
field specifies an operation that does not require input data. Otherwise, this
data is specific to the function being performed.</p><p><b>fpvOutBufferIsNULL:</b>  A Boolean value
specifying whether the caller wants to retrieve the length of the data. MUST be
set to TRUE (0x00000001) if the caller wants only to retrieve the length of the
data; otherwise, it MUST be set to FALSE (0x00000000). </p><dl>
<dd>
<table><thead>
  <tr>
   <th>
   <p>Name</p>
   </th>
   <th>
   <p>Value</p>
   </th>
  </tr>
 </thead><tbody><tr>
  <td>FALSE</td>
  <td>0x00000000</td>
 </tr><tr>
  <td>TRUE</td>
  <td>0x00000001</td>
 </tr></tbody></table>
</dd></dl><p><b>cbOutBufferSize:</b>  The maximum size
of the buffer to be returned. This field MUST be ignored if fpvOutBufferIsNULL
is set to TRUE (0x00000001).</p></div>