logging data from micrologix 1500 to SQL

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Thread Starter

Kumaran

Hi I am doing a project that requires data from a micrologix 1500 to be logged to a database on a PC (MS SQL server 7 or similar). How could I go about doing this? I am thinking of using an OPC server (from softwaretoolbox.com) and connecting to that from VB before writing to the database. Is there a better way of doing this? cost is definitely a factor for this project hence the method described above. thanks Kumaran
 
J
Kumaran, You could also use an ActiveX control to connect VB to the PLC -- Software Toolbox also has an ActiveX control that can be used to connect to the Micrologix PLCs that might consider depending upon your requirements. To be fair, you can get the DF1 protocol document from AB and implement it all yourself using VB Comm to control the serial port if you like. You should of course weigh for your own needs the cost of engineering and testing your own driver versus the cost of an off the shelf driver with available tech support. Spoken only as an engineer - nothing more -- ok list readers :) - John Weber
 
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Anthony Kerstens

Someone with a stingy boss or a dead PCMK? Someone working with archaic systems? Someone who just wants something quick and dirty for that old PLC they have running the water-pump and lights at their cottage? (no, just a "guy" I know :) Anthony Kerstens P.Eng.
 
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Alex Pavloff

> To be fair, you can get the DF1 protocol document from AB and > implement it all yourself using VB Comm to control the serial port if you > like. You should of course weigh for your own needs the cost of engineering and > testing your own driver versus the cost of an off the shelf > driver with available tech support. Spoken only as an engineer - nothing > more -- ok list readers :) - Why is it that we see people nearly every week on this list asking how they talk to <Insert flavor-of-the-week> PLC with Microsoft Visual Basic. I just got done cleaning up some DF1 code that was originally written 9 years ago (and ported continuously since), and it was a pain. If I could get around writing my own code to talk to a PLC, I would. So why are there so many people that want to write their own code to talk to a PLC? I go to your website and see that it will cost $499 to get an ActiveX Omron control, with no runtime fees. Seems to me that if I had better things to worry about, like getting a complete system up and running, $499 would save me much heartache. So once again, I ask to those who constantly ask for "talking to their PLC with MSComm".... Why don't you guys buy rather than build?
 
J
Pat, Some PLCs like the AB Micrologix - that is the built in connection in the PLC without going to a network like DeviceNet and additional hardware - the user said he was cost sensitive, so I take that to mean he wasn't interested in buying more hardware -- OK :) Given my choice i'd always rather go ethernet -- but if the PLC hardware doesn't support ethernet, what am I to do besides tell the user "ditch your PLC?" John Weber
 
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Psst....Want to know a secret...... Whilst people like HP make special chips for interfacing things like scanners and printers to USB ports, more humble and specialist equipment manufacturers are making use of a chip that make the apparatus appear to be interfaced on a fast UART. The hardware of serial ports may die out (at least RS232, 485 is alive and kicking in industrial comms), the art of interfacing to UARTS will be with us for some time!
 
> Why don't you guys buy rather than build? Actually I had no intention of trying to write my own driver unless all else failed. (it is only a very small part of the whole project after all) In fact that activex control looks very attractive. I just wanted to know what other ways there were (besides the one i mentioned) of going about this. >Who is still programming or connecting through >the serial port? I was thinking of using that because it would be easy have it connected to a modem for remotely logging the data. However that's more likely to be a future extension to the current project. Ethernet would be nice but i don't think that's available for the micrologix just yet (at least not within the timeframe for my project). Devicenet may be an option but can you connect a modem on it? thanks alot! Kumaran
 
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amora fibrianto

find an OPC/DDE server.........but make sure that they're compatible with your micrologix.... Using RSLinx will give you a clear and much more saver way......but ........ you know the price... next step, DDE-ing your application.....In this case your excel, word, or even MS-SQL will act as a DDE/OPC client......of clourse you will need to write a code for it.....but it's much more simpler than writing your own code just to communicate to the ML1500....... All you have to concern is your application..... and i think Rockwell has their sample code on doing DDE with their equipment/software ....... hope this would be help..... Rgrds Amora fibrianto engineering dept. Somit Automation
 
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Juergen Rensen

We provide an in-expensive product called "OPC Office Link" you might find useful. It allows sampling directly into SQL server, Access, etc. and linking into Excel from any OPC server, without writing any code (please see www.ris.co.nz).
 
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