difference between APDU command between contact and contactless Interface
<p>I have a question about APDU format in contact and contactless Interface. I have an ACR122U contactless card reader and i studied it's API (v2.1). According to the document, apdu format in contactless mode is different from contact mode. for example SelectApplet command in contact mode is: </p>

<pre><code>Command &gt;&gt; 00 A4 04 00 09 [A0,00,00,03,08,00,00,10,00] 00
Response &lt;&lt;61 19

Command APDU &gt;&gt; 00 C0 00 00 19
Response APDU &lt;&lt;61 17 4F 06 00 00 10 00 01 00 79 0D 4F 0B A0 00 00 03 08 00 00 10 00 01 03 90 00
</code></pre>

<p>but in contactless mode is:</p>

<pre><code>Command APDU &gt;&gt; FF 00 00 00 12 d4 40 01 00 a4 04 00 09 a0 00 00 03 08 00 00 10 00 1a
Response APDU &lt;&lt; 61 20   

Command APDU &gt;&gt; FF C0 00 00 20
Response APDU &lt;&lt; d5 41 00 61 17 4f 06 00 00 10 00 01 00 79 0d 4f 0b a0 00 00 03 08 00 00 10 00 01 03 90 00 90 00
</code></pre>

<p>But when i search on web, they mentioned that there is no difference between APDU format. Am i wrong and there is another solution to send APDU to contactless interface?</p>

<p>Thanks a lot.</p>