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MAKING THE CHANGE

From Standalone to Internet Appliance
by Edward Steinfeld

Start ý Internet Appliance Options ý Web Technology ý Cost and Options ý Web Server Inside ý Use Common Components ý Sources and PDF

INTERNET APPLIANCE OPTIONS

Unless you want to create a proprietary network solution, the obvious choice for Internet support is web technology. An Internet appliance can be another client on the network using either an embedded web browser or embedded web client in the appliance. There are major differences between a web browser and a simple web client.

The Internet appliance can be a web server delivering HTML graphic pages to a web browser somewhere on the network. There are a number of ways a potential Internet appliance can become a web server. Later, Iýll describe one of the possible solutions that can significantly reduce manufacturing cost. First, the original equipment manufacturer (OEM) must be convinced that using web technology is a sound and effective solution.

CHALLENGES OF NETWORKING

What do you face when your customer is considering turning his instrument into an Internet appliance? You need to first select a network operating system or protocol. Today the choice is easy. If the device has no baggage of an existing network to support, the choice is TCP/IP. TCP/IP software stacks are readily available, and some are tuned for embedded and real-time operation.

Next, what computer and software platforms will communicate with the instrument? Not only are there many different kinds of computers, but each computer may be running a different operating system. And, if the connected computers are to have human interaction with the instrument, you have the problem of supporting multiple user interfaces.

Even the connection to a file server can be a problem. What file system or protocol does it useýNTFS, NFS, FAT-32, FTP, XML, and so on?

Finally, a major problem is software distribution of the user interface and keeping track of each new user.

These OEM problems have been obstacles since the first distributed process control systems. Networking problems are expensive to solve when using the older, traditional methods of development. Often, it is easier to limit the access to the device, rather than solve all the problems. In the past, OEMs developed their own proprietary network protocol and user interface in order to keep the total system manageable. Sometimes, they had to restrict access to a known set of users and platforms.

Today, there is an easy solution available for nearly all of these problems. If the total system of extended users is primarily for data transfer, monitoring, and control (usually setup), the solution is to use Internet and web technology.

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