Accessing an RFID reader via a computer from a server
Question: On a computer I want to run a web-based application which is served by a
server and this application have to access an RFID reader.

I have set this computer to connect to the server via wireless LAN and connect
to the RFID reader via an Ethernet cable (tried both straight through and
crossover cable). The reader cannot connect to the server directly because of
the mobility needed.

Setting up the connection appear in the image below. The server assigned IP
address for the computer using DHCP. Connection between the computer and the
reader have set by static.

![enter image description here](http://i.stack.imgur.com/d6OXI.png)

Clearly, the computer can access both the server and the reader but the server
cannot access the reader as I needed.

EDIT:

The application is developed using Python with Django framework. To connect to
the reader I just simply used `socket`.

    
    
    import socket
    
    HOST = '192.168.1.21'
    PORT = 50007
    soc = socket.socket(socket.AF_INET, socket.SOCK_STREAM)
    soc.settimeout(2)
    soc.connect((HOST, PORT))
    


Answer: I would implement a java-applet and upload it on the server. When user opens a
page from this server, java applet loads and starts working. Applet is running
on the user's computer context and can access RFID reader, and pass this
information to the server.

If accessing RFID-reader requires to involve dll-libraries or any native OS
modules, then this applet has to be signed. Use keytool and jarsigner tools
from Java SDK to sign the applet before uploading it to the server.

[Here you can find information on java
networking](http://download.oracle.com/javase/tutorial/networking/index.html).

[And here you can find information on java applet
technology](http://download.oracle.com/javase/tutorial/deployment/applet/)

