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CMore potential safety issue

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  • racrowd
    started a topic CMore potential safety issue

    CMore potential safety issue

    We noticed today that if you use 2 or more fingers on the CMore panel at one time, it will activate the object directly between the two fingers. I think this could be considered a safety problem since it could inadvertently start a machine. I don't remember seeing this in any of the documentation regarding the touch screens. I guess, I just wanted to make sure that Automation Direct was aware of this.

  • dieselvette
    replied
    I don't mean to be argumentative racrowd, but ANY touch-panel is not a "safe" means of control for dangerous equipment, That is why the E-STOP and tactile switches exist. Even if it was a $20,000 HMI would you still trust it - a TOUCH screen? Communication integrity & speed have improved dramatically over the last 20-30 years, and touch screens are much more reliable, but really how much faith do you have in it?

    I always go into it with the assumption that the HMI will fail, and you don't know what it's failure mode will be. Similar in concept to fail-safe wiring, using NC switches in series for E-Stop, etc. And imagine if you unplug the HMI, can there be a "managed" shutdown without E-stop damaging equipment/product?

    I sometimes add a switches/buttons next to the HMI for some basic control functions too - goal is that the machine can function without the HMI present at all. Maybe not practicable with every machine, but worth considering.

    Originally posted by MikeMc View Post
    ....once you have logged in, you have to keep logging in every time you touch another passworded control.
    A possible solution for this is duplicate screens - "normal" screen has pw protected objects; but "logged-in" screen is pw protected itself with no protected objects (this screen may also have links to several other "inaccessible" screens). So once you've entered pw for that screen, never again until you "log out" (or you can set C-more to go to X screen every hour, or whatever).

    There is also the touch & hold option for objects, or use an internal tag to open a "confirmation" pop-up which is a button tied to PLC tag.

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  • MikeMc
    replied
    Firmware issue

    Originally posted by JOEng View Post
    From the manual page 2-4 and other pages, the touch screen is designed to respond to a single touch. Touching the screen in multiple places at the same time may cause an unexpected object to activate.
    Just as leaning on the touchscreen or bumping the touchscreen may activate an unintended object, care should be taken to interact with the touch screen (any control interface) intentionally and in accordance with the design of the hardware as well as the project.
    The firmware should insure that you cannot activate an object by touching the panel in more that one location at a time. This I consider to be a safety issue and that is why our screens have all operating controls (set point, start/stop, and such) passworded. The operators hate us for this but that is another issue with ADC, once you have logged in, you have to keep logging in every time you touch another passworded control.

    Mike McClanahan
    Global Production Solutions
    Senior Automation Engineer

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  • MikeMc
    replied
    What operators

    Originally posted by Adisharr View Post
    Oh wait - good point
    What operators

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  • Adisharr
    replied
    Originally posted by scott.lawrence View Post
    wait... I thought that's what we are doing, albeit slowly
    Oh wait - good point

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  • scott.lawrence
    replied
    Originally posted by Adisharr View Post
    It would be much easier if we could just get rid of the operators altogether


    wait... I thought that's what we are doing, albeit slowly

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  • Adisharr
    replied
    It would be much easier if we could just get rid of the operators altogether It's always tiresome trying to think of every way someone could screw something up. Sometimes it's me

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  • racrowd
    replied
    I agree with both of you. I use logic to ensure that nothing unsafe could happen. You have to admit that human error could still occur. Looking at it from the OSHA point of view, if an action occurred without the operator starting that action, then that is the machines fault. I guess since it is documented, then using multiple fingers at the same time might be considered human error or a failure in properly training the operator.

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  • Adisharr
    replied
    You have to account for all these types of things. Any accidental key press could do the same thing. If there's a potential safety hazard then the machine should not start.

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  • JOEng
    replied
    From the manual page 2-4 and other pages, the touch screen is designed to respond to a single touch. Touching the screen in multiple places at the same time may cause an unexpected object to activate.
    Just as leaning on the touchscreen or bumping the touchscreen may activate an unintended object, care should be taken to interact with the touch screen (any control interface) intentionally and in accordance with the design of the hardware as well as the project.

    Leave a comment:

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