Defect and BG logic

    Hi everyone,

    The structure of my program is as follow :

    I do have a MAIN programs call by the PLC and inside the Main a select instruction to call any other programs depending of a variable from the PLC
    On top of that , i've BG logic , nothing surprising and everything is running fine.

    I wanna add to my program some defect of the gripper which is basically as follow :
    Before doing my last Linear pick mouvement : I need to control if the gripper is open, if not the program must be stop until the DI[Gripper_Open] = On

    Doing this is quite simple inside a program (not the BG)
    IF (DI[60:Gripper_open]=OFF)
    GO[4:Robot_Defect]=1
    CALL F_Defect
    ENDIF

    Inside the F_Detect TP Program
    R[6:Defect_Robot]=GO[4:Robot_Defect]

    SELECT R[6:Defect_Robot] =1, JUMP LBL[1]
    =2, JUMP LBL[2]
    =3, JUMP LBL[3]

    LBL[1]
    Message [Gripper not open before picking]
    WAIT DI[60:Gripper_open]=ON
    JUMP LBL[999]

    As you can see the robot is not really hold or pause, it is simply a wait instruction, which is what I need, the robot will kept going is the DI is active


    The current issue is , I want to permanently control that the gripper remains close once my robot has pick up the product.
    I must use those information inside the background logic , but the background logic cannot call any program , nor contain any WAIT instruction (logic : it must loop).
    I could use the RUN instructions instead of CALL inside the BG , to run the F_detect independently
    How should I use a judicious program for this defect information?

    Should I use 2 BG logic (does fanuc allowing that?)
    Instead of calling for F_defect, it might be better to use a register that the BC logic will see and then run the F_defect ? ( to prevent the F_defect being call twice (once by the main and also run by the BGlogic)
    How do expert like you handle those situation :face_with_tongue: ?
    Thank in advance.

    Fanuc does allow up to 8 BG logic programs, there is more info in the HandlingTool manual or the help button on the pendant.

    Also you can use the "run" instruction from BG logic instead of the "call" instruction. The link below has some good info on how that works.

    How to RUN FANUC Programs Concurrently with the RUN statement - ONE Robotics Company


    In the past I have used something along the lines of this to monitor the status of a gripper while holding a part. The F[enableGripCheck] would need to be turned on after you pick up the part and turned off before you place the part.

    Code
    *psuedocode
*running in BG logic

IF (F[enableGripCheck] AND (DI[GripNotOK]) THEN
F[enableGripCheck=(OFF)
!handle dropped part however you want
ENDIF

    You may want to consider using the skip function in your program instead of BG logic. To me this seems like it would have more control over the situation and can trigger movements as needed whereas BG cant trigger movements. Doing it this way you can stop the robot from performing the move if it has dropped the part and you can "recover" faster

    Hello, I guess monitoring 2 BG Logic at the same time should do the job.
    On staubli, an expert told me once it is recommand to use 1 BG program only. Having 2 or more BG at time might greatly reduce processing speed.

    Quote from HawkME

    In the past I have either used the skip function to monitor the gripper or use a PLC to monitor the signal and stop the robot. It is possible to do with BG logic or condition handlers as well.

    Does ABORD or Pause fonction works in BG logic ? or do you use signal to PLC to stop the robot in the BG logic

    Thank you for your response and merry christmas.

    It can work in BG Logic if you are controlling the UI signals from there (indirectly with flags).

    Normally I use the PLC to control the UI signals. If you don't have a PLC then BG logic can act like a mini PLC. Also you can have multiple sections of logic in a single BG Logic program.


    Merry Christmas!

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