PLC Ladder logic Analog programming for Analog Input

Discussion in 'Programmer's Corner' started by irfan16, Jul 1, 2012.

  1. irfan16

    irfan16 Thread Starter New Member

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    Dear All

    I am facing difficulty in programming the PLC for analog input. I have analog input that varies from 0~5volt. I want to develop ladder logic so that for 2.5 volt at input output should activate alarm and at 5volt input another alarm at out put should be activated. I am using ABB PM571 PLC. Can anybody guide me how I develop the ladder logic for above stated requirement.

    I shall be thankfull to you.

    Kind Regards

    Muhammad Irfan
    Student
  2. strantor

    strantor Well-Known Member

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    I'm not familiar with ABB software, but look in your instruction set and find a comparator function.
  3. irfan16

    irfan16 Thread Starter New Member

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    Can you send me any example. How I read analog input?
  4. irfan16

    irfan16 Thread Starter New Member

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    Dear Sir

    Can you send me example code.
  5. strantor

    strantor Well-Known Member

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    No, I do not have ABB software. Sorry.
  6. panic mode

    panic mode Well-Known Member

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    i never used ABB controller but the idea is the same:
    - get software and manuals
    - get part number of the analog input card and it's manual
    - configure/map I/Os
    - write program to read I/Os (may require enabling it, setting network etc depending on type of used I/O)
    - use compare instructions to set bit when value is in certain range
    - download program to controller and monitor...

    quick check with google suggests that software can be CoDeSyS (you can get it for free) but this would require target files for ABB plc (not free). all manuals are on abb website. good luck...
  7. irfan16

    irfan16 Thread Starter New Member

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    Dear Sir

    I have alraedy install ABB software codesys and configure the inputs and outputs. But I am not familiar that how i develop code to read analog input? I just need guideline that what function or block I should use to read the status of analog input.
  8. irfan16

    irfan16 Thread Starter New Member

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    If you have example code for PLC of any brand (i.e Siemens,Mitsubishi,Omron etc) Please send it as I need just idea that how to read analog input status.
  9. irfan16

    irfan16 Thread Starter New Member

    Joined:
    Dec 29, 2011
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    Location:
    Malaysia
    Dear Sir

    I have alraedy install ABB software codesys and configure the inputs and outputs. But I am not familiar that how i develop code to read analog input? I just need guideline that what function or block I should use to read the status of analog input.
  10. GetDeviceInfo

    GetDeviceInfo Senior Member

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    I'm not familiar with the system your working with, but I'd think that the converted input/output would resolve to a word or double word with simple address or tag, no different than any other I/O.

    Take care with your wording. 'Status' has special meaning in this field.
  11. panic mode

    panic mode Well-Known Member

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    get the manual for your analog input card, it should have code sample.
  12. strantor

    strantor Well-Known Member

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    OP hasn't been back in 5 days. He's likely either figured it out or given up by now.
  13. AJAY kARTHICK

    AJAY kARTHICK New Member

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    Dear sir,
    use LIN_TRAFO block for reading anlog input module........
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