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waterboy

collecting RLinx data

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You can find any of Rockwell's List Prices HERE But after reviewing this topic I think we have gotten a little off. You were looking for more writing software and less purchased hardware weren't you?

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Yes you are right of course, And the price tag of $2500 for that module puts me right back on track . Now, getting back to reality, I'm looking for a mostly software solution that I can poke at in my spare time.

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Two options to ponder. Can you initiate a DDE request using a vbscript? vbscripts are executed on the server side so if RsLinx was on your server then it would work IF vbscript can initiate a DDE request Have your webpage open an Excel file. It can do this without actually opening Excel. Excel will do the DDE request, the parse the data in your web page. Tons of work but cheaper (still $800 or so)

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The Excel technique may be what I have to do but I was hoping for a bit better formatting of data as well. If I could use ODBC then I can use ASP scripts and I have some understanding of that process. If I could only interrogate the iFix database directly... I have some homework ahead of me. btw on a completely unrelated note, Whats this "WARN 0%" meter mean on my posts? I don't recall seeing that before. Edited by waterboy

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I wouldn't worry about it. If it says 0% then you are fine. MrPLC is a growing forum and this is a new tool that is being tried to help us keep the forum on a professional level.

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FactorySQL is $1895, not $4000 and the free trial will run for 2 hours at a time. Topserver is a rebranded Kepware OPC Server - basically performing the same functionality as RSLinx, which you already have. Kepware makes a good product. RSLinx is a good product. They're pretty similar as far as this application goes. Ken's suggestion with Excel via a DDE connection to Linx would work for a small, non-critical application. It is not terribly difficult to do. You should know that there is a (stupid) US patent protecting that (#5,038,318). Doing projects like this via Excel is pretty clunky. Think: computer must autologin, macros enabled, spreadsheet autoopen, no user touches the thing. Not exactly the pinnacle of reliability. DDE is old and clunky these days too. An MS service pack among many other things could mess up your app. If you're familiar with VB programming you can do this for free. The OPC foundation has free sample code to make OPC requests that would work via RSLinx (you said you have a copy of pro). Also look at OPC toolboxes, etc. You might check Sourceforge...I would highly recommend going OPC since you already have RSLinx versus any native AB driver projects you might stumble upon there. You'd really strike it if you can find an LGPL OPC datalogger project. I'll take a look. Edited by Nathan

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My mistake, when I went to the site I just hit "price comparision" thinking that would be the place to find the price compared to other brands. I see I was looking atthe wrong thing and that it is just what you said. Sorry about that. I thought the same thing about DDE (even a 6 year old software program we use for particle counters didn't recommend DDE back then) but I didn't see many alternatives. (didn't know about a patent! How odd!) I have some small familiarity with VB and obviously I will have to get more into it anyway so I'll look at some samples to see if it is within my skillset now or will be later. I even have a 1998 disk that says "OPC Server Toolkit from Intelliution" so that's a start. That'll be more fun anyway. Thanks for the correction and advice, All of you. Time to go pester the OPC foundation folks. Edited by waterboy

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There are several threads that deal with RsLinx and OPC. They might give you a starting point. Search this section Here is one http://forums.mrplc.com/index.php?showtopic=9292

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Thank you for that too. You guys have been fantastic!

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Searches under 4 charactors don't work so well so do a search for visual basic instead of opc. It should grab them all but you will have to sort through them and find the OPC ones

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The patent is the most ridiculous thing ever! Someone deserves to get smacked for that one! OPC(DA) is already a pretty old tech - based on MS DCOM, but it's the best (most standard) out there now. They're working on OPC-UA, which will use: XML, web services, security models, etc, etc. The lead OPC guy was one of the Rockwell's top programmers. He's in good with both FactoryTalk and Archestra and some of the better features of both with be integrated into OPC-UA - A non-proprietary standard is a win-win for all. I'd play with some of the VB or even VBA scripting with OPC. There's lots of examples out there. If you have specific OPC questions I can run them by our programmers and might be of some assistance. I'm not sure if there are any good OPC forums. I'll have to check...

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I would appreciate your help more than I can express!

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Look for the free software from Ron Gage. You can use it to directly talk to at least the PLC-5's. There is a similar package out there that handles Ethernet/IP though it isn't nearly as "clean" in terms of reading. From that you can probably easily build a web page with Python or Ruby on Rails or TurboGears (Python Rails).

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Good call Paul. If you're only dealing with one type of PLC a specific package/project would work fine. All those scripting languages he mentioned are relatively easy to use and very powerful. I haven't dealt with the "on rails" versions with the web APIs. Do they support a lot of AJAX? Maybe I'm "old school"...I'm still a fan of PHP. Waterboy - could you describe what you're trying to accomplish with the project?

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If you are familiar with VB you can download VB express here: http://msdn.microsoft.com/vstudio/express/ Here is an excel spreadsheet from AB using OPC I have also attached the file I have experienced some difficulty with AB's upgrade of their KB lately: http://domino.automation.rockwell.com/appl...5256AFB0059FE9F VB forum for help with VB code: www.codeguru.com A sample VB.net application from Kepware not sure of any restriction of use but it will give you a good start change the referenced OPC Server to RsiOPCAuto (Rockwell's OPC DLL packaged with RSLinx) and it will work fine as written to display data it does not store the data anywhere: http://www.kepware.com/Temp/Simple_VB_dot_Net_OPC.zip I am working on a custom data collector myself right now using Visual Studio 2005 (VB 2005) one note if you try to attempt a custom VB app Micro$oft stopped packing/including DDE with VB.net from it's inception. So DDE is not even an option unless you are going to use VB6 or earlier. Also watch out this is one project that can grow into a monster. My collector has an Access Database as the bacbone of the colletor sytem to hold tags, system configurations, etc, as well as real time values. All tranactions are handled by Visual Basic code. It also caches all data collection points in the Access Database waits for positive confirmation of successful transmition to the SQL Server 2005 database before destruction of cached data. Of course if the data you will be collecting is critical you also will need to incorporate caching in your PLC(s), something you may want to include up front. I guess my point is their is a lot to consider and the cost of a canned system may be cheap compared to the time you will spend on it. In my case their is not one package that can do all we need it to, and do it all well, so we opted for the custom route. rslopcauto.xls

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I looked up Ron Gage and his stuff is all Linux. I barely get Windows at this point. The end result of this project is a web page with whatever info on it that the managers want. They don't need very much and it's not worth putting the SCADA software on thier machine (well, I don't think so now, I might change my mind after trying to make this work;-)) This is an experiment that I will do in my spare time to see what the limitations are. If I am able to read PLC values with a web browser there are many places where thats all that is needed, If I can write to them there are many more. One of the more interesting issues I am also trying to address is our remote sites. We have ~30 remote stations all linked through radio telemetry. It would be a bonus to see if what the operators see at the plant is what I am sending from the remote site. That could be done with a browser based view that is accessible over a cellular web link. Edited by waterboy

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You're right of course, the canned system is more than likely the cost effective way to go and I can see how this could grow into a huge project with a life of it's own. But I have to try to see how the process works. I don't even need to collect and store anything, I just want to display it in as close to realtime as I can. I volunteer at a non-profit as a network admin and one of the perks is a premium MSDN subscription, So I have all the tools I need, just not the expertise... yet. Thanks for the links, I have a lot to digest over what seemed at first to be pretty straightforward.

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