SBC that hosts a web page

Discussion in 'General Electronics Chat' started by strantor, Apr 10, 2012.

  1. strantor

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    With my previous company, instead of using taditional PLCs, they used DIN-rail mounted Beckhoff SBCs (single board computer). You could plug in a laptop with ethernet into the SBC, go to your web browser, and type in the IP address of the SBC and a web page which was hosted on the SBC would appear. The SBC was also connected via ethernet to I/O modules. From the SBC-hosted page, you could monitor the I/O, and network status. I believe all the software on the SBC was written by software engineers within the company, so if I were to buy one of these SBCs I would not automatically have that same capability.

    After a series of unfortunate events & much frustration today with Allen Bradley's crappy crap, I started to think about these SBCs. I was thinking it would be so damned easy to use a PLC where the programming software is already in the PLC. Just plug in ethernet, type in IP address in the browser, and a Java-based programming page appears. No more special 300$ cable for each and every different model# of PLC. No more compatibility issues. No more fussy sofware, with fussy installation proceduress & windows version conflicts. No more memory-hogging expansive software suites and fussy licensing procedures. No more monthly patches & updates. No more going into configuration to change the backplane layout - I/O modules are plug & play hot-swappable, stackable in any order - need another one, just slap it on the end. No more staking your livelihood on the hopeful survival of a single-point failure laptop that has all your kilobucks worth of special software on it, and watching it go down the drain as someone trips over your power cord and brings it down to the deck in 5 pieces; you can use ANY computer that might be around; windows, linux, unix, mac, makes no difference - if it can display a web page and all the keys work, it can be your PLC programmer (you could even use a HMI that might be already connected via ethernet). No more need for using outdated laptops because they're the only ones with serial ports.

    Then I started to think, well if I've thought about it, someone else probably already has, and beat me to the punch, as usual. So I'm asking here, is there anything on the market that meets my description?
     
  2. strantor

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    To expound on that, maybe have NEMA4X/IP67 rated remote I/O modules that don't even need to be inside enclosures, connected via ethernet to eliminate thousands of miles of single conductor signal wires going back to the PLC.
     
  3. Kermit2

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    strantor likes this.
  4. GetDeviceInfo

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    http://ab.rockwellautomation.com/IO/1799-Embedded-IO

    doesn't get much easier.
     
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  5. mcgyvr

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    Have you tried Automation directs Click PLC series.. They are very low price/free software,etc.. Not exactly what you wanted but they work great without having to sell your soul to AB or any of the other overpriced PLC companies..
     
  6. strantor

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    A coworker keeps talking about thes click PLCs. he has one at home and goes home & plays with it everyday. I have never seen or used one, but have heard of them and plan to look into them.
     
  7. GetDeviceInfo

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    I've got a seven card slc 5/04 system running a process in the plant. <$300 on ebay. Yes, I had the programming software, and the RS232 ported laptop.
     
  8. strantor

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    Well, it's good you got a 5/04 and not a 5/01 or else you would have needed the special 600$ 1747-PIC box & cable, in addition to a special computer that has XP SP2 on it, because it won't work with any version of windows after that. Another great example of of what I'm talking about. I have a special computer here that I had to go out and find just to interface with one PLC in the plant; it's an old p.o.s. desktop tower that I have to lug over there if I want to go online with it. I had to buy the cable and the computer and an additional software license just to make one stupid change to a single instruction, and I haven't needed it again since.
     
  9. MrChips

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  10. MrChips

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    With internet connectivity you get all the ease and convenience of installation, maintenance, monitoring and interoperability. But this also makes it vulnerable to malicious attack and sabotage: read STUXNET.

    http://en.wikipedia.org/wiki/Stuxnet
     
  11. GetDeviceInfo

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    a 5/03/04 upgrade off of ebay is less than $200. I partion xp pro as a boot option on all my laptops because most of my industrial software won't work beyond. I've also found when purchasing laptops is that some older moldels are more robust than the newer offerings, cost way less, and have that much needed RS232 port, which is required for my siemens,fanucs,modicons and TI PLCs.

    I've experimented with my own SBC constructions. For one client I have compiled Labview VIs running on windows xpe on an old wyse pico board. The I/O is there exsisting TI simantic over modbus. My latest experiment is basically the same but with an Atmel AVR over usb as the I/O driver. Although this is my 'hobby', it makes little sense for an industrial client to deviate from industry standards.

    In the last month or two, I have been tasked to evaluate a companies exposure as they contemplate transitioning thier core product process. Part of this is measuring thier ability to respond effectively to breakdowns, and more specifically thier access to resources. With controllogix processors running around $10k from our local supplier, with 2 day delay, do you stock, upgrade other systems to create redundancy, or send every one home. It's a bit of a bonus for me, because every manufacturer in the area knows I have a couple of spares 'for sale'.
     
  12. strantor

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    That's a much better idea than having a special dedicated computer. I might take a page from your book, can't believe I didn't think of that. It still seems like a work-around for a less than ideal technology though. Less than ideal, but necessary for the time being, as the technology is alreaday in existence and installed in machines that will be around for years to come. My idea is to render the technology obsolete in machines produced now, so that the work-around won't be necessary in the distant future.
    That's sounds pretty clever, but unfortunately I don't have the experience to know what you;re talking about.
    So, basically an arduino? I've used arduino in industrial environment. Right now I have an arduino-based fault tester embedded into one of my armor machines, and my supervisor is requesting I build 3 more for new machines we have on order, plus a few spares. So I'm going to be playing with lots of arduinos soon. I will be interfacing them with Controllogix PLCs, should be fun.
    good idea again. I have a spare SLC500, that's all. This company has been through 3 managers in the past 2 years. the first one wanted plenty of spares of everything on hand, so we had lots. The second one came in and considered our stores to be excessive and an inefficient use of space, and made us "reduce our storage footprint" so we threw lots of stuff away. We went by the guideline "if you haven't used it in the past 2 years and don't reasonably forsee yourself using it in the next 2 years, then get rid of it". We threw thousands upon thousands of dollars worth of unused stock in the trash; I'm talking everything from 20K$ gearboxes to 3$ toggle switches. (the trunk of a car serves as a nice trash bin sometimes). A noticeable trend in increased downtime was the result, and probably one of the reasons why we don't have that manager anymore. Now the new manager criticizes our paltry stockpile and takes every opportunity to make a big deal when something breaks and we have to wait on a part (while simultaneously trying to make us occupy less space).
     
  13. strantor

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    Hmmm... very interesting. Maybe NSASpook knows something about it...
     
  14. GetDeviceInfo

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    I buy a barebones 32U4 with USB connector and standoffs. I have employed code chunks from the arduino suite. I'd be interested on your thoughts of connecting to Controllogix. I started playing with Devicenet on a can controller, but implementing the protocol is too time consuming .
     
  15. strantor

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    Well I haven't done it yet, it's still just a hair-brained vision. I was thinking to either get an ethernet shield or communicate via RS-232 and implement the protocol (it's already written & out there on the net somewhere). The RS-232 I'm pretty sure I could pull off; I have successfully sent & recieved commands from my laptop that way & I don't why it would be any harder to do with a PLC. The Ethernet, I've never played with, that would be a new frontier for me. If both of those options fail, All I really need is a few digital outputs & inputs from arduino to PLC and I could use relays.
     
  16. GetDeviceInfo

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    However, today I did share your grief. After failing to load an RS232(DH485) driver into RSLinx for an older PV550, I discovered that I have to back up to Windows xp sp2. And I had planned on a relaxing evening.
     
  17. strantor

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    The only good thing I can think of about Rockwell recently is their tech support. It is the best tech support I have ever dealt with; and rightfully so, considering you have to pay for it.
     
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