Internet connectivity: The time is right and the technology is ready for you
By Olaf Pfeiffer and John Rodrigues
[ Introduction
| Internet Connectivity Parameters | Case
Study ]
[ Adapting
the Software | Dynamic Web Pages
| Feedback with Forms ]
[ Continuous Refresh | Security
| Summary ]
| < Previous Page |
Internet Connectivity Parameters
Due to a lack of standards regarding "remote access" implementation for embedded systems*, the number of technical variations is great. For example, which physical media should one assume? Ethernet? If the answer is yes, is there a DHCP server to assign an IP address or will a static IP address need to be assigned? Alternately, if the choice is to dial-up via a modem, which phone number and ISP will be chosen, which protocols and services will be needed for support (Email, Web Server, and/or FTP Server), and what about reliability and security issues?
Perhaps the biggest challenge in determining a design route is the "gateway question." Do we allow our embedded device to directly communicate with the Internet - or will all communication be funneled through a gateway? And if a gateway is used, where does that come from? Is it an external product? Or is it part of the embedded system - potentially running on one of many controllers within the application?
The preceding question highlights a trend in the embedded industry in which embedded systems often consist of several microcontrollers communicating with each other. This is especially true for any machinery with multiple sensors and/or actuators. If a local network already exists (something like a proprietary serial bus, CAN/CANopen, DeviceNet, LON or USB - just to name a few), the logical approach is to try to implement a gateway between the local network and the Internet, thereby providing "remote access" to all local nodes.
*To address the standardization of the methods and protocols used to access embedded devices, the authors of this article currently work with several companies and universities on an Internet Draft that eventually might become an RFC (Request For Comments) published with the RFC-Editor (www.rfc-editor.org). For further information on Embedded Internetworking and to read the latest about the Internet Draft on "Embedded Internetworking with Remote Access", please go to www.embeddedinternetworking.com
| < Previous Page |
[ Introduction
| Internet Connectivity Parameters | Case
Study ]
[ Adapting
the Software | Dynamic Web Pages
| Feedback with Forms ]
[ Continuous Refresh | Security
| Summary ]
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