View Full Version : Embedded Web Servers
April 26th, 2002, 10:33 AM
I'm a 4th year student (one year till graduation) and I started looking around for some interesting graduation / final projects. One idea that came to mind involves remote browser-based monitoring and control of an industrial automation process (over the Internet).
So I did a search on Google for 'embedded web server' and came up with thousands of links showing just as many products that fall into this category. Kinda hard to choose from :rolleyes:
I want to ask for your help in choosing one of those beasts. If any of you has any experience with things such as embedded web servers and remote monitoring / control using web browsers, could you please give me some details, like device manufacturer, good points / weak points, pricing information, development tools and so on.
Thanks in advance !
April 26th, 2002, 11:35 AM
Contact AutomatinDirect.com. They have (or at least had) a web page link to a sample system that would let you monitor a system real time over the web.
April 26th, 2002, 02:33 PM
Check the Modicon web site. They have a Web server card for there Quantum serie PLC. Its FANTASTIC!
April 26th, 2002, 03:50 PM
If you're talking about an embedded web server for a PLC, that's bitter subject. Groupe Schnieder (aka Modicon) holds a patent that they claim gives them the exclusive right to interface a PLC with the web (or, a right to force companies to pay through the nose for the licence to do so).
You may want to look at Spectrum Control's WebPort (http://www.spectrumcontrols.com/webport.htm), which has been developed, but cannot be released due to this.
This might be why Tom wasn't sure about AutomationDirect's product. There was some discussion of this on Controls.com - check through their archives (try searching on "Patent")
Thousands of hits, huh? Groupe Schneider's laywers must be busy.
April 26th, 2002, 10:04 PM
You may want to look at Omron's ONC product, it can be used as an embedded controler, a gateway, soft PLC or a server. It is a cool product, it is not an PLC module but a stand alone unit. It is also less expensive than the Modicon PLC.
It is true that Modicon has a patent on a PLC with an embedded web server.
April 26th, 2002, 10:22 PM
hmmm, Bit theres your senior year project. Modicon has a patent on THEIR net server deal, why not determine what they are doing that is patented and look for another solution (that may also be patented) or can be used without infringing.
We are talking the web here...ie tcp/ip...netbeui..etc they cant patent that. They cant patent using a micro controller.
Seems alot of options may be open for someone to investigate, wish I was smart enough too.
Make a law student friend if possible, the association may be worthwhile.
April 27th, 2002, 03:49 AM
Ok, thanks for all the replies, I'll further investigate all your recommendations.
I also think I should give you some more details on the project.
It's about an automated 21st century house. Yes, you read it correctly, an automated house. It consits of an 80C552 microcontroller-based system that can control / monitor in-house temperature, lights, doors, security system and so on. This microcontroller system has an RS-232 port that can be used to send control commands and read system status. No PLC is involved.
Although a PLC could do the job just as well, this part of the project has already been developed (the hardware only). The software will eventually be developed by me using the C programming language.
We are currently investigating different possibilities to control the system from a remote location.
Another student has taken the task to build a telephone based remote monitoring / control solution using a specific Integrated Circuit and the DTMF (Dual-Tone Multi-Frequency) interface. His module will have an RS-232 port on one side and a phone-line interface on the other side. We are also looking at some GSM modems for this purpose.
So I was thinking about developing a web-based solution for monitoring / control. I'm looking for an embedded web server with an Ethernet (or PPP) interface on one side and an RS-232 interface on the other side, so I can plug it between the existing system and an Internet connection.
April 27th, 2002, 04:46 AM
Z-world has a relatively cheap board with an Ethernet interface. It can be programmed in 'C' to issue some html pages. However, I would not use the web page approach and instead write a local inteface in VB and communicate to the remote controller using Modbus/TCP. This is much faster than using web pages and takes up much less space in the embedded device.
There are motion controllers that can be controlled over the internet. I have one customer monitoring a motion controller in Mexico from the USA. The main obstacle is security. I have two motion controllers on the internet now that I use to do demos and tech support. Whem a customer calls, we tell him how to download our setup/monitoring software and give him the IP address of the motion controller. One of the motion controllers controls two motors and the other is connected to an old 60's style analog simulator that simulates a hydraulic axis with MDT or analog feedback. This has been most handy because the customer can learn how to tune the motion controller's PID using our equipment. He can also download the state machine into our motion controller and I can then see where the errors are and fix them. Then customer can then upload the working state machine code. This has saved us lots of time and money because we have reduced the need send people to these sites to do training or sales demonstrations.
I have also demonstrated controlling the motion controller from over half way across the US over the internet using VB and monitored the motion controllers using Excel's VBA. We wrote an ActiveX control that interfaces the Ethernet appllication protocol to Visual Basic to do this.
Maybe this will provide some inspiration. There are other ways of using the internet to control, monitor and support embedded applications over the internet than using bulky html code.
Check out Z-world and Modbus/TCP.
April 27th, 2002, 07:08 AM
try out this website: http://www.bcl-online.de/. They have an embedded webserver with quite a lot of possibilities. If your using a domotics system, it should be possible to construct a gateway between internet and your automated house. If you are using a PLC to automate the house, then different companies have ready-made solutions. Siemens as an example has ethernetcards for use with S7-300/400 (CP343-5 IT and CP443-5 IT) which can be connected to an Intranet. Your study could be how to couple them to the internet. Good luck!
April 28th, 2002, 09:26 AM
I actually did that a couple of times when I was in college, but we would make up a ASP page with VB script in it, to interface to a DLL, and that DLL would interface to the parallel port, and the parallel port would either be communicating via modbus to a modicon PLC, or use a rack of solid state relays to control something, or use actual analog cards in the computer; For your application you could probably interface directly to your microcontroller.
Here is a website of a sample project, http://xrobocam.ati.stlawrencec.on.ca/
If you wanted more examples, email me at email@example.com and I can give you some example code (when i get my own computer up and running again).
April 1st, 2007, 10:05 AM
Bit, can you tell me if there was a result for the gsm part of your friends project, where could i find it or could you give me a contact/email, im currently doing exactly that, PLC based GSM automation of a house, if you could give me some hints it would be great !!!
April 4th, 2007, 11:29 AM
Check out B&R products. The current HMI/PLC I am using has TCP/IP built in, with a Web Server, FTP, ETC, as well as VNC functionality. Also in your case, you can program in C if you choose. The page running on the web server is in ASP, and it does allow you to operate the device through the web browser.