clueless PLC user

MrPLC Member
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Everything posted by clueless PLC user

  1. S7-200 programming/replacement

    Hello, As my username implies, I am way out of my comfort zone here, but here goes. Have a Kuhlman steam sterilzer, just shy of 20 years old, that uses the aforementioned CPU(?), to further expand on the numbers, 216-2AF22-OXBO. Daisy chained below this are four 222-1BF22-OXAQ modules. The problem I have is it no longer properly reads atomospheric pressure, which when idle should be around 14.7. Instead it jumps all over the place, causing an issue whenever a cycle is started. I did find a known good replacement for the 222-1BF22-OXAQ to eliminate that possibility, but after the vendor installed it, still no change. Vendor also checked things with a signal generator, all good there....pressure transducer that generates signal good, but replaced this to be sure, still no change. This leaves just the main CPU, and according to him this is no longer serviceable. That said, I see these used all over and am curious if ours can either be repaired, or if I can send ours in so a replacement can be sent back programmed just the way ours is currently. Please dumb it down for me with any questions, etc. I'm in my comfort zone under the hood of a diesel engine, not in the cabinet of this machine. I know just enough to be dangerous. Appreciate any directions folks, thank you
  2. S7-200 programming/replacement

    Well folks, purchased a refurbed EM 231 and the old girl is up and running again after a year long furlough! I was almost giddy when I saw the PSIA read 14.7 again instead of 10.4, 10.7,12.3........ Much appreciate the info and knowledge I stumbled across here from you guys, it's proven to be invaluable. Plan now is I am going to order some spare modules, along with a CPU(providing I can still get it programmed but I am making headway there). At the least it buys us some time before we end up sinking a large sum into this machine with all updated electronics. Am curious if anyone is familiar with the Siemens touch panels? Likely just a matter of time before it gives out, and I've located some online. Does the panel also have to be programmed so the layout is the same as the current one? It's of the 6AV6 545 family, and also appears no longer supported. 
  3. S7-200 programming/replacement

    Appreciate the link to the info As mentioend, I too wonder if the wrong module was tested, but at any rate why the 1st slot was replaced when it's not the issue. I am tempted to roll the dice, purchase a good known 231 and see what happens.  I did check the dip switches just to be sure they were set up according to the schematic, and they are still set as they were from the factory. Thanks again folks for the ideas/info
  4. S7-200 programming/replacement

    Good info, thanks again folks. So what you are saying is, I could try a known good  EM 321 and the PLC will still allow that 1st slot for my two wires. There are other modules below this one, however they are only used for RTD's and are stated as such in the model # AI2-RTD The one I am referring to says it's a 12 bit, AI4x12bit Was able to attach a pic this time. Slot 3 is the one that reads the transducer.....slot one is the one the vendor replaced, of course the reason it's missng the slot 1 sticker. Probably nothing wrong with the original I kept    
  5. S7-200 programming/replacement

    The pressure transducer is hooked up to a 24V terminal strip, then loops around to the module. Readings are displayed on a Sematic touch screen control panel. Here is where things get interesting, to me at least, and not sure why I didn't catch this earlier......like I said it's been a year since I looked at this sterilzer as we didn't really need it in operation. The module that the transducer hooks into is a EM 231  231-OHC22-OXAO I have no idea why the vendor thought it would work to try a different EM 222, that as far as I can tell has nothing to do with this transducer. Is it possible the EM 231 is bad? I did try the other three empty spots on that module but no change, guessing that has something to do with the way the CPU is programmed. I would post a pic but for some reason I can't, even if it's the correct upload size.  In reference to your earlier question about the part #, that was the correct one, at least it's what is listed on the front of the housing.  
  6. S7-200 programming/replacement

    Pretty sure all he did was a hook signal generator up to the EM 222, of which this machine has 5, and checked it there? This was about a year ago so I can't recall all the details. We event tried a new EM 222 which made no difference. I know this sounds rudimentary here but I'm just giving the nuts and bolts version of what I know, nuts and bolts.    
  7. S7-200 programming/replacement

    I"m in the NW corner of IA
  8. S7-200 programming/replacement

    Appreciate the replies folks. Yes, I was told it's an old setup and no longer supported, so no suprise there, and do remember the vendor telling me he would need to find someone with access to some older software. That was as far as he coould help me out, and did suggest upgrading the entire system but then didn't express much interest due to being busy with larger projects. Of course, the owners want to go the low cost route if possible, but I do see this as an issue even if we are able to address it as a crutch for now. I do recall him using the signal generator directly on the analog side, yes.