Enable/Disable outputs

  • Hi


    I have (let say) a cylinder extending by DO[6] or R0[4]. Doesn't matter


    I want/need to extend it only when robot is in running condition
    I know I can use background,etc, etc but the problem still remains because I can go to the DO and turn it on (pushing the "green" button).


    So, How do I take that feature out ? I want to control that output 120% automatically , no human can change status in manual mode

    Retired but still helping

  • Hello,


    Can you elaborate? Do you mean turning the DO manually from the DO screen on the TP? Why bglogic is not possible or even interconnect? The DO will be turned to the necessary state, even if somebody wants to change it.

  • Thanks for the answer


    This is for Waterjet.


    I want the waterjet gun with 100.000 psi to be on, only when the robot is in auto and running the cycle . So, it is safe
    I dont want a human to be able to turn that output on ever (not in teach , not in auto) never

    Retired but still helping

  • Aren't there DO (In Menu->Setup->General) that could be use with background logic that would do just that, on our arcmate when the selector was on Auto the "Weld enabled" came on and green lights were flashing when a cycle was running

  • andreic Could work but I see complications with customers


    SBrousseau and Sergei. Your idea doesnt stop anybody from just selecting I/O, Digital and turn the DO on (make it green)


    Let me put it on another way. On Motoman, to solve this issue I use Concurrent I/O. Not only I disable the output from user, I make to go on/off under certain conditions

    Retired but still helping

  • I've set up a similar safeguard to prevent a tool changer from being unlocked.


    BG logic:


    If UO[3], DO[5] =F[5]
    If !UO[3], DO[5] = off


    Use F[5] in your program to turn on/off the waterjet. If the program is not running it will not let it turn on, even if you manually force the DO on, it will turn back off immediately (couple msec). Set F[5] off at initialization of main program in case operator accidentally turned it on. If program is paused then resumed, so will the waterjet.


    Sent from my VS985 4G using Tapatalk

  • Hello mr. Fabian Munoz,

    I used this concept for triggering an alarm. If robot was idle for too long in auto mode i will generate an alarm.

    USE PMC or BG logic, what-ever you feel easy.


    U can find TP enable or disable feedback in so7 ( pls check for your robot ) it will say whether ur robot is in normal mode ( manual ) or production mode ( auto ).
    One of your DI or Do ( range between 80 -85 ) i cant remember, it will tel u whether your robot is idle or working.
    So assign on digital output as dummy ( i.e., this will be used to switch on and off your water jet output in program)


    so now u can make logic


    BG logic example:
    use mixed logic instruction.
    if so7 = on ( TP enable ) and dxx ( robot busy) = on and do = on ( dummy output, u can set this output were ever u need) then dox ( water jet output ) = on


    PMC:


    use above logic in ladder diagram.


    240% auto control... :icon_smile: :icon_smile: :icon_smile:


    Note : u cant force on and off your water jet output even in manual mode.
    u should stop ( BG or PMC logic whatever u used ) to force this output.


    hope this helps.

    Edited once, last by suganthyadav ().

  • I use BG logic for this all the time. If a DO it's manually forced, the BG logic immediately turns it back off. If you really are worried about an operator defeating that then either password protect or run it thru a PLC.


    Sent from my VS985 4G using Tapatalk


  • ... Sergei. Your idea doesnt stop anybody from just selecting I/O, Digital and turn the DO on (make it green) ...


    Correct. But, if the condition is False, it will not activate the valve RO.
    The condition was specified as "robot is in auto and running the cycle" in your question.
    You did not say that even under that conditions you want to forbid manual activation.


    If so, let the running program activate two bits (e.g. flags).
    Only when both are On, the background logic will activate the valve.
    Let the background logic reset each after certain time being On alone.
    The time should be short enough to make impossible consecutive manual activation of both.

  • "If you can endanger people by turning on WaterJet, you shoud use DCS .."


    I'm not sure about that, dha. Indeed, "safety" is whatever the controller is engineered to do. The code runs just the same if it is safe as it is not.


    That is, there is no "safe" state except decided by logic as programmed. by a human. safety either hardware or software is determined on a case by case basis - as you know


    While I accept logic in safety plcs and dual-check-safety might be preferable to other methods, let;s accept that DCS is probably prohibitive in some cases.


    These proprietary systems are tools - just tools - to achieve the engineering safety standards your team lives by -


    The controller doesn't ask you when it arms the servo and brakes enable - it sees an input and acts on it - I don't see how we can make computers emotional - unless we tell them


  • I agree. But you have to secure critical functions of the machine and if the worst happens you are responsible.


    Code written in DCS cannot be stoped or modified without a password.

  • run your output to a safety relay and have your systems safety voltage run the coil. DCS I/O is your best bet, it is all dual-chain and can give you a safety rated signal for T1/T2/Auto. you can also set it up to ensure that it remains in an area, restrict joint positions, speeds ect.

  • Hi


    Yes I could, that idea works as far as safety but there is a catch.


    Waterjet process is very fast (the ON/OFF) In the past we had problem when the output goes through the PLC and then to the valve, That takes time when you are doing a normal cycle. After many WJ cells we noticed that even putting the valve on the arm (axis 2/3) it was delaying the cuts, we actually put the valve right on top of the WJ on/off valve to avoid any delays. Then you get only few inches of the air travelling from the valve to the head to actuate.
    Believe or not that fraction of a second is important because the robot is already moving without water.when you start cutting or cutting before starts moving


    The reason for my question is that (i'm repeating myself) doing with Motoman is very simple (just using concurrent i/o) which is basically what you wrote using the PLC. I thought it was going to take no time to do something similar with Fanuc. So not only a can do the automatic part on Motoman, i actually disable the output from the screen.
    It's gotta be a way to disable the F4 (green colour) on the DO Fanuc screens


    I don't want to use DCS, and relays and PLCS and $$$ options, it should be a simple way and not only for waterjet.


    I haven't been in the shop to play with it, being on the road a lot

    Retired but still helping

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