PLC via Internet

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Thread Starter

Toni Kaesbeck

All: I need to connect a PLC (which has a RS232 serial port) via Internet to a PC. The PLC is in a remote unmanned station with the only possibility to connect via a wireless phone modem to a Internet Service provider. I have found converters from the serial link into TCP/IP, but how can I dial up and automatically reconnect to an ISP, if there is no support on that PLC? Thanks for all replies! Toni Kaesbeck
 
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Not really sure I understand, but is there a PC attached to the PLC? If so then one way to do this would be for you to download a remote control software like PC Anywhere (by symantech) and install it on both computers -one in your office and one at the station. With PC anywhere you can dial into that computer and control it remotely as if you were sitting right there (except it is a little slower because of the communication). With PC anywhere you can connect via internet or direct dial up. so if your remote PC is connected to an internet service provider you can just connect to it via internet. Otherwise you can simply dial up from your computer to the remote one. If you don't have a PC at the remote station, you will need some software that will act as a server and is able to receive phone calls, I have never seen a stand alone PLC with Internet capability but hey, I'm still too young to have seen it all ... :) If this is the case, please let me know who makes these – I’d like to learn more about them. If you do have a stand alone PLC with internet capability your best bet would be to contact the manufacturer - they should be able to walk you through it step by step. Hope this helps Peter > All: > > I need to connect a PLC (which has a RS232 serial port) via Internet to a PC. > > The PLC is in a remote unmanned station with the only possibility to connect via a wireless phone modem to a Internet Service provider. I have found converters from the serial link into TCP/IP, but how can I dial up and automatically reconnect to an ISP, if there is no support on that PLC? > > Thanks for all replies! > > Toni Kaesbeck
 
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David Wooden Omron

Please send some more information, such as what brand and model PLC, what kind of communication you wish to initiate, what protocols are to be used, and any other relevant information you can think of. My first thought is that you may need to install a PC or other Internet enabled device at the remote location to handle initiation and protocol conversion, or possibly upgrade the PLC to a more recent unit that could be capable of those things. David Wooden Automation and Enterprise Solutions Omron Electronics LLC 1300 Basswood Road Suite 200 Schaumburg, IL 60173 (847) 884-7034 [email protected]
 
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Cory Schaeffer

Maybe I'm missing the point, but I don't see the need for the ISP. You will need a modem any way you look at it, so why not just dial up to the PLC directly from the PC. No is required at the PLC end and most PLC's have some form of dial up connection. Hope this helps... Cory Schaeffer Information Products Holland, MI
 
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I don't know your protocol, but if you can do Modbus, check out the Modbus Earth Station offered by NR&D at www.niobrara.com. It's an interesting idea for satellite connectivity via internet.
 
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Toni Kaesbeck

Thanks for all the replies. Some more info: - The PLC is "a proprietary hardware" (as is the SCADA), not an off the shelf brand and I have RS232 and 485 on it - I was trying to see, if I can do without a PC just adding a "little Internet box" - The PLC's are in a remote location (several hundreds of miles) with no phone cable and I need to use wireless dial-up to an ISP - It needs to be permanent on and automatically reconnect in case of connection failure "I have never seen a stand alone PLC with Internet capability but hey, I'm still too young to have seen it all ... :)" >>>> I guess we will be soon old enough to see one, even if it's not mine ;-) Thanks Toni Kaesbeck
 
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Kirk S. Hegwood

I have not done it as of yet, but Automationdirect.com has a standalone PLC (DL05 $99) that can be combined with a modem. It is shown on page 31 of their new catalog. Good luck, Kirk S. Hegwood President Signing for Hegwood Electric Service, Inc. [email protected]ctric.com
 
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Rob Entzinger Schneider Automation

Schneider Electric have a web server card that slots into the backplane of the controller. For the Premium the module is a TSX ETY xxx For the Quantum the module is a 140 NOE xxx xxx different models of the module. One sets up HTML pages containing jave applets. One can then read information from the controller with any standard web browser. If you visit http://public.modicon.com/Transpar.nsf/ContentContainer?OpenFrameset select livedemo on the left and continue you will be live on a PLC. Rob E.
 
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IP OMER BIN ABDUL AZIZ

One of the advantages that I can think of is that the PLC data can be made available on the world wide web. For example, you can send emails and provide web access using Siemens PLCs. Clear skies! Omer
 
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http://arsrobotica.com/display.php3?blogid=322 Check out the link to the SitePlayer. You can have any device with a serial link become a WWW server on ethernet without any TCP/IP programming. I am experimenting with one now, and it is very nice. I haven't tried it with PLCs yet, but I want to. The maker offers a complete software package to simulate the SitePlayer. You use a PC with their free software, and when the application is working you can then buy the development kit ($99) and set up the final version. This way all the development and testing is free. I have no ties to the company other than I am playing with one of their devices. Ed Speaking for me, not for Starbucks. . .
 
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Steven Landau

This works fine inside of a facility, but I have not been able to find a way to economically have a 24/7 dial-up connection provided by my ISP, which I can get the PLC to re-connect if it goes down. Anybody done this?? Steve Landau VP Controls & Automation SPEC 92 Montvale Ave Stoneham MA 02180 Office: 781-438-3337 Fax: 603-843-5097 Cell: 617-908-9232 e-mail: [email protected] e-mail to pager: [email protected] (short messages only) ----"THE ENGINEERS WHO BUILD"----
 
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A pair of net connected Linux boxes, one on each end and a few dozen lines of C. These can be old 486's. Support is built in for automatic reconnection. One end should have a static IP address. We've been doing this sort of thing since the net belonged to DARPA. Total cost should be less than half of any of the proprietary solutions. Any UNIX systems programmer can write this for you, check with any university. No big deal. Regards cww
 
Another similiar product from B&R (www.br-automation.com), a PLC with Web-Server in-built. The PLC is actually a small PC-Based system with RTOS kernal, but the interface to user is a standard PLC programming environment. It is a rather new product from this company, you can contact their local representative for details. Mark
 
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Get a static IP dialup from an ISP. Get an cheap PC from somewhere. Set it up with Linux. Use the diald daemon to keep a connection permanently up. Use the built-in ipchains utility to foward the relevant HTTP ports to the PLC. The PC becomes a transparent link between the PLC and you, with the added bonus of large amounts of configurable security (accessing the PLC data only after being authenticated via private/public key encryption, for one).
 
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Adrian Moore

May I suggest you investigate the Dedicated Engines MIMIC unit. See http://www.dedicatedengines.com/. The MIMIC bolt-on website enables you to view remote sites on active SCADA-style graphic websites over the Internet, via direct dial phone line, or over your own company intranet. Connecting directly to the existing raw I/O of legacy industrial equipment, the MIMIC takes signals and produces them as SCADA-style graphics on active web pages. The web pages can be viewed on any PC connected to your network using a standard web browser such as Internet Explorer. Contact Ton Harrison, Director for more information including a serial connection to the PLC!!!
 
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Preston Todd Johnson

You might try using National Instruments Lookout and their Serial to Ethernet Converter. Lookout will function as your webserver with a browser based HMI client to your PLC. The serial to ethernet converter adds a serial port to your webserver's system. So to Lookout and your Webclient, your server is simply a long serial cable. You can find info on these products at www.ni.com/lookout and www.ni.com/serial. Good Luck Preston Todd Johnson Interspace Electronics [email protected]
 
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