System variable for Robot in Motion

    I am working on the Fanuc R2000iC robot with r30iB plus controller. After the robot reaches a certain specific position, I need the PLC to know the robot has reached the desired position.

    I need to do this without using reference positions. So I switched ON a digital output when the robot reached a position and used the $MOR_GRP[1].ROB_MOVE variable in BG Logic to know whether the robot is in motion. When the variable returns 1, the DO is switched off in BG logic. This works fine in manual mode but in auto mode, even if the logical instruction gets executed, the output gets switched off.

    How to make the above logic run in auto mode?

    Any help would be appreciated. Thanks. :smiling_face:

    How is your movement program looks like?

    You have J/L movement and on next line you set DO? If so, what is approximation setting of movement (fine, cnt0, cntX?

    Or are you setting DO in your movement instruction? Like J ... DB 0.0 DOx = ON?

    Maybe use pulse for timing output. That way you dont need to turn it off in BG.

    It sounds like your DO is turned off instantly, because robot is still moving.

    You are likelly missing the DO update betwheen PLC cycle scans and I/O updates, every BGlogic loop runs at a minimum of 8ms tick rate, it depends on the controller type, only way to ensure you are executing the bglogic at a minimum of 8ms is to set it to priority hight, if it's on normal it can vary.


    And even that way, it seems I/O update time on the robot side is done every 20ms or so (at least with siemens cards), so if a signal changes OFF/ON/OFF on that interval you will not notice on the PLC side.

    This is a problem I have right now with a communication I need to do in real time, I've not found a way to transfer I/O changes faster than that even implementing cyclic interrupts on the plc side, the communication is slower than what I need.


    Please, provide an example of your normal TP program and also the BGLogic one, in order to help you we need to know how are you handling the movements and I/O changes.

    I do not know, if it is helps You, but one of the BG logoc what we are using:

    123: !Robot actual position ;

    124: GO[11:4336:CurrPosX]=($SCR_GRP[1].$MCH_POS_X*10) ;

    125: GO[12:61953:CurrPosY]=($SCR_GRP[1].$MCH_POS_Y*10) ;

    126: GO[13:5523:CurrPosZ]=($SCR_GRP[1].$MCH_POS_Z*10) ;

    127: GO[14:65523:CurrPosW]=($SCR_GRP[1].$MCH_POS_W*100) ;

    128: GO[15:64052:CurrPosP]=($SCR_GRP[1].$MCH_POS_P*100) ;

    129: GO[16:14064:CurrPosR]=($SCR_GRP[1].$MCH_POS_R*100) ;

    I see, take into account that MCH_POS data is only updated while robot is executing a program both in T1 or AUTO, this variables are not updated while jogging the robot manually.

    If you need to get the data while jogging you can get the same data from this other variables:

    If you want the position from world:

    Code
    $SV_INFO[1].$CART_POS[1]

    If you want the position from the current selected UFRAME:

    Code
    $SV_INFO[1].$CART_POS_UF[1]

    But... with the code you provided, I do not see any movement or where and how you SET/RESET that variable, please, provide the TP code where you set the variable DO to ON and the one where you set the DO to OFF.

    Quote from Patrik Paukov

    How is your movement program looks like?

    You have J/L movement and on next line you set DO? If so, what is approximation setting of movement (fine, cnt0, cntX?

    Or are you setting DO in your movement instruction? Like J ... DB 0.0 DOx = ON?

    Maybe use pulse for timing output. That way you dont need to turn it off in BG.

    It sounds like your DO is turned off instantly, because robot is still moving.

    These are linear movements with approximation setting FINE when the robot set DO ON. I am setting DO in a new instruction like DO[65: Robot At Weld Position] = ON.

    For working this now, I have removed resetting DO in BG. Now resetting in next program before next movement starts but I would like to do this based upon the robot position; like even I jogged the robot, DO should switch OFF.

    I will check by using pulse in this case. Thanks. :thumbs_up:

    Thanks for the involvement.

    Below is a part of PNS program.

    11:LBL[1] ;

    12: ;

    13: R[20:TEST]=100 ;

    14: OVERRIDE=R[7:Old_OVR] ;

    15: R[20:TEST]=0 ;

    16: CALL CONFIRMORDER ;

    17: //OVERRIDE=20% ;

    18: R[20:TEST]=1 ;

    19: SELECT R[1:Work No]=5,CALL RECOVERY_HOME ;

    20: =10,CALL PICK_LH_PALLATE ;

    21: =20,CALL PICK_RH_PALLET ;

    22: =30,CALL WELD_1 ;

    23: =40,CALL WELD_2 ;

    24: =50,CALL WELD_3 ;

    25: =60,CALL WELD_4 ;

    26: =70,CALL WELD_5 ;

    27: =80,CALL WELD_6 ;

    28: =90,CALL WELD_7 ;

    29: =100,CALL WELD_8 ;

    30: =130,CALL DROP_PARK_STATION ;

    31: =140,CALL PICK_PARK_STATION ;

    32: =110,CALL DROP_LH_PALLATE ;

    33: =120,CALL DROP_RH_PALLATE ;

    34: ELSE,JMP LBL[110] ;

    35: ;

    36: JMP LBL[1] ;

    37: ;

    38: LBL[110] ;

    39: MESSAGE[Wrong Work Nn] ;

    40: JMP LBL[1] ;

    Now when R[1]=30; WELD_1 program is executed. Below is a part of WELD_1 program.

    61:J PR[30:PreWeld1] 85% CNT100 ;

    62: R[5:Recover Data]=15 ;

    63: ;

    64:L PR[31:Weld1] 500mm/sec FINE ;

    65: R[5:Recover Data]=16 ;

    66: //L P[2] 100mm/sec FINE ;

    67: ;

    68: //DO[104:OFF:WELD1]=ON ;

    69: CALL CONFIRM_POS(67) ;

    In CONFIRM_POS program, DO is set. Number of the DO is AR (67 in this case). So DO[67] is set. Now the cursor goes to CONFIRMORDER program as soon as it completes WELD_1. Below is the CONFIRMORDER program.

    1: LBL[2] ;

    2: ;

    3: DO[31:OFF:Action Finish]=ON ;

    4: ;

    5: WAIT DI[19:OFF:Spare 1]=ON ;

    6: ;

    7: DO[31:OFF:Action Finish]=OFF ;

    8: ;

    9: GO[1:5:WORK NO ACK]=0 ;

    10: ;

    11: DO[26:OFF:Read Prg No]=OFF ;

    12: ;

    13: DO[28:OFF:Read Work No]=OFF ;

    14: ;

    15: DO[27:OFF:Wait Work No]=ON ;

    16: ;

    17: WAIT DI[27:OFF:Work No Valid]=ON ;

    18: ;

    19: R[1:Work No]=GI[1:0:Work No] ;

    20: ;

    21: GO[1:5:WORK NO ACK]=R[1:Work No] ;

    22: ;

    23: DO[28:OFF:Read Work No]=ON ;

    24: ;

    25: IF R[1:Work No]=0 OR DI[28:OFF:Work No OK]=OFF OR R[1:Work No]=R[4:Last Work No],JMP LBL[2] ;

    26: ;

    27: DO[27:OFF:Wait Work No]=OFF ;

    28: ;

    29: DO[28:OFF:Read Work No]=OFF ;

    In BG logic program, following is the code.

    DO[100:OFF:Robot In Motion]=($MOR_GRP[1].$ROB_MOVE) ;

    IF (DO[100:OFF:Robot In Motion]=ON) THEN ;

    DO[67:OFF:Weld1]=OFF ;

    ENDIF ;

    I have also checked by using flags but same result. This works in Manual mode but in Auto mode, when the cursor goes to CONFIRMORDER, output goes off.

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