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Thread: PLC upload or download?

  1. #1

    PLC upload or download?

    Hi,
    We have a little confusion about the way the above terms are used. My associate worker says that download is from PLC to PC because he relates it to the internet to PC. But I am saying that the opposite is true because most PLC software mentions it this way. What do you think?
    Thanks in advance for your replies.

  2. #2
    Join Date
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    Re: PLC upload or download?

    When I programmed PLC's, we always called transfering the program to the PLC downloading.

    Maybe downloading is from a larger computer to a smaller less powerful one. So you would download from the internet (a giant network of servers) to your computer. You would also download from your PC to a PLC which is usually smaller and less powerful than PC's.

    Or maybe you download a program to where it is used, and upload to store or edit a program.

    Steve

  3. #3
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    Re: PLC upload or download?

    According to the online dictionary "infoplease", download is from a larger to a smaller computer or to a perhiperal device. Upload is from a smaller to a larger computer.

    So you are right, and your associate is wrong.

    Steve

  4. #4
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    Re: PLC upload or download?

    There is no standard convention. I have over 5 different PLC programs on my computer right now some say download, some say upload, but most now say Transfer.

    My experience has been:
    ELECTRONIC people often say download TO a PC, while ELECTRICAL people usually say download FROM a PC.
    Just because you can, doesn't mean you should.

  5. #5
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    Re: PLC upload or download?

    Can you beleive IEEE actually has an "official" definition:"

    IEEE Std 610.5-1990. IEEE Standard Glossary of Data Management Terminology.
    download (A) To transfer some collection of data from a computer memory to another storage location. (B) To transfer
    some collection of data from the memory of one computer to the memory of a second computer that is relatively smaller
    than the first; for example, to transfer data from a mainframe computer to a microcomputer. (C) 610.5-1990

    upload (A) To transfer some collection of data from some storage location to a computer memory. (B) To transfer some
    collection of data from the memory of a small computer to the memory of a relatively larger computer; for example, to transfer data from a microcomputer to a mainframe computer.
    (C) 610.5-1990
    "Bob"
    Robert B. Alexander, P.E.
    "I know that you believe you understand what you think the NEC says, but I am not sure you realize that what you read is not what it means." (Corollary to Charlie's Rule)

  6. #6
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    Re: PLC upload or download?

    The real question is why do programmers continue to use these confusing terms? Bigger computer in what respect.......physically, memory, power?

    Many programs use terms such as "Load PLC" and "Save PLC" (or similar for for VFD drives, message displays, etc.) to make it clear which way the program is being transferred.

  7. #7
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    Re: PLC upload or download?

    "Load PLC" or "Save PLC"??? Now that's confusing.

    Download and Upload seem quite obvious to me. They are well defined as stated above, and it is usually obvious which computer is larger. Any company that would call downloading from a PLC to a PC probably refers to voltage as current. And they probably call a loose wire a "short".

    Maybe the companies that refer to downloading to a PC are trying to imply that their PLC is better and faster than the PC's.

    Sorry for the rant, but some software companies really drive me crazy. Please don't even mention that soft-Micro company.

    Steve

  8. #8
    Join Date
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    Location
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    Re: PLC upload or download?

    In my opinion you download from and upload to the computer that actually uses the program information to do work. In the case of the PLC, the PLC processor does the work, so you upload the program instructions to it and download from it.
    Don
    Don, Illinois
    "It is the first responsibility of every citizen to question authority." B Franklin

  9. #9

    Re: PLC upload or download?

    I worked for Modicon. Download is from PC to PLC. Upload is from PLC to PC. Period.

  10. #10

    Re: PLC upload or download?

    I worked for Modicon. Download is from PC to PLC. Upload is from PLC to PC. Period.

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