Very new at PLC programming need a lot of help

Discussion in 'Programmer's Corner' started by Dorrance, Jul 7, 2011.

  1. Dorrance

    Thread Starter New Member

    Feb 19, 2011
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    Hello I have been working as an electrical maintenance technician for about 15 years. I am very familiar with PLC's but in all my years I haven't found anyone who could teach me programming. I do know and understand ladder logic. So I bought an Allen Bradley micrologix 1000, I got this one because it is out dated, has all AC inputs, and Rockwell gives a free version of micro lite for programming. my first problem (but sure not my last LOL) is that the AB 1000 takes a serial DB9 plug on my laptop I run windows vista and all I have are USB ports. I have a Trip light USB to serial converter model U209-000-R but I haven’t had any luck with sinking. I am unsure if the converter works? All I know is I can’t get any communication from the PLC. Could someone help?
     
  2. davebee

    Well-Known Member

    Oct 22, 2008
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    I'd suggest checking that the right COM number is in the PC code.

    I've used a USB to serial converter to program a microcontroller, and it worked pretty well except for two things.

    First, where the built-in serial ports used to come up as COM1 or COM2, the USB ports come up in all sorts of varieties - COM7, COM8, COM9, and it can change if other USB devices get added to the USB hub before connecting the microcontroller programmer.

    So every time I start a new programming session, I've got to check that the program is configured with the current correct COM number.

    Second, while I'm programming my serial device, if I plug a new USB device like a printer into the hub, the adapter will send a glitch to the serial device. It isn't fatal but in my case, it resets the microcontroller unexpectedly, so it isn't really desired behavior.
     
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  3. strantor

    AAC Fanatic!

    Oct 3, 2010
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    +1
    and also, any time you reboot the laptop, depending on what's plugged in at the time, the "virtual serial port" may change.

    Also, some of the old AB PLCs use DH485 or other wierd protocol, which you may need to setup using your virtual serial port software; not sure how that works, never tried it.

    Another thing, if you are using an AB PIC device to connect, RSLogix only works with the PIC on WIN XP SP1 & SP2. If you have upgraded to SP3 or higher, you will have to wipe out windows and find a copy of an earlier version.
     
  4. Dorrance

    Thread Starter New Member

    Feb 19, 2011
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    Sorry if I posted in the wrong place this is my 3rd post but the first I have had responses to.
    Ok I have gotten the USB to serial adapter to work but still not able to link from what I have been reading I needed to install RS linxs so I did (it took about 2 hours) with that I am getting closer to the PLC but not quite there.
    Now "highway plus but 0 nodes are found”?
    Also on the same window it states that Server RSlinxs: Type not a PLC,SLC,orCL
    So that is where I am I am not using a PIC and I know what a node is but not really sure how to find it on the PLC I am using.
    Once again thx for the help.
     
  5. strantor

    AAC Fanatic!

    Oct 3, 2010
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    First off, you should be using an RS232 crossover cable or a serial cable with a null modem. (that is unless you have the micrologix model with the special cable with the round end 1761-cbl-pm02; in which case just use that cable only)

    (make sure the PLC is connected to the laptop and powered on at this point - also wouldn't hurt to be in PROG mode, if it has a selector on the PLC)

    Ok,
    1. open RSLinx, at the top menu click communications>configure drivers

    2. stop & delete whatever drivers are running.

    3. in the top drop down menu (available driver types), select RS232 DF1 devices, and click 'add new'

    4. don't rename it, click ok

    5. a box should pop up with driver settings. select the proper comm port (you may have to go through all of them until you find the right one; as discussed, when using the virtual comm port, the numbers will change)

    6. select "device" : "SLC-CH0/Micro/PanelView"

    7. click auto configure; if auto configure fails, try a different comm port (refer to #3)

    8. once auto configure works properly, minimize RSLinx and go into RSLOGIX500.

    9. go to comms>system comms and highlight "AB_DF1, DH485" - you should see your PLC there.

    10. Click on your PLC and then click "download"

    -now you should see whatever ladder logic is stored in the PLC when you go online-

    11. close the comms box and go online
     
    Last edited: Jul 7, 2011
  6. strantor

    AAC Fanatic!

    Oct 3, 2010
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    That's my title. Maintenance Electrical Technician. There are a few of us maintenance guys spread about the ranks here at AAC, but mostly its electronics guys. You won't find too many folks around here with up-to-date PLC know-how.

    Nobody taught it to me either. Learned by fiddling around. Once you get the feel for RSLogix programming environment, try getting into the compactlogix line; they have text-based programming similar to Basic. Past experience programming in MS VisualBasic & C as a kid helped me jump into that. It's a steep learning curve but it opens a world of possibilities that Ladder Logic can't.

    Sorry, this is the first of your posts that Strantor has seen.

    There are other forums out there more geared towards the industrial technician. mrplc.com, plctalk.net, et. al. but they seem feebly unpopulated. I have had a question posted on those forums for >3 months before it got a reply before. Your best bet for getting support on Rockwell/Allen Bradley stuff is to call Rockwell Tech support. they give good answer fast, but you have to pay for them. See if your company can open a tech support account with them.
     
  7. Dorrance

    Thread Starter New Member

    Feb 19, 2011
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    Thanks Strantor this is what I have been looking for. I won’t have time today to try it I have to work. I believe my company already has an account with AB but I have never used I work night shift about 14hrs on a rotating schedule. But I could ask them if I could use on my days off.
    You seem to have a good understanding of what I am doing I am using a 1761-cbl-pm02 cable :)
    When I started this company I told them I wanted to learn programming there were 2 people who said they know how but neither really do. So once again I’m on my own. All the jobs I apply for the first questions I get asked is can I program? So I know what kind of doors that will open for me.
    I hope you keep an eye on this thread I really like your help. So thanks for posting in such detail. I will write when I get a chance to try out all the info you have given me.
     
  8. strantor

    AAC Fanatic!

    Oct 3, 2010
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    Just checking back; did this work?
     
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  9. Dorrance

    Thread Starter New Member

    Feb 19, 2011
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    Thanks Strantor for writing back I just tried, followed your instructions just like wrote and they worked perfect. I don’t know how to tank you enough you have showed me more in one post than I have learned in years. I still have a couple questions but with what you have given me I am sure I am on my way.
    My question is if I click “comm.>clear processor memory” will this do just that? The possessor I have is used and has a program on it that is all timers and different logics. I want to write my own programs I built a test station (very crude) but I want to understand all that is going on and be able to change when needed.
    I see you are from Texas. My mom lives there and has been complaining about the heat. I live in Grand Rapids MI now but once owned a house in Irvine DFW area. MI is nice but I don’t care for snowy winters.
    Once again Thx.
     
  10. strantor

    AAC Fanatic!

    Oct 3, 2010
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    I would assume so, but I have never clicked that. Its a scary button. I don't know if there's something other than the program included in "processor memory". It is probably totally safe to click that, but superstitiously I never will. Just make your program and download it to the PLC. Your program will wipe out the current one.,
    its hot as balls here
     
  11. gerty

    AAC Fanatic!

    Aug 30, 2007
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    Before you do that, I would save a copy of the program first.
    And yes it will wipe out the existing program and leave you with a clean slate.
    Here at the school we use Logix Pro plc simulator, you can go to :
    www.thelearningpit.com and download a trial (30day) version. It'll walk you through the whole process from connections to basic programming. You can buy the program disk for about $40.
     
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