Conveyor tracking without hardware trigger

gea_gfantechi

Hi everyone,

I need to set up a conveyor tracking application in which I cannot directly wire a sensor to the switch input of CMT, as my trigger is actually a logic condition, and its expression may change at runtime.

Is there any way to provide a soft trigger switch via RAPID? I am aware that I will introduce time uncertainty but my conveyor moves slowly and I need no extreme positioning accuracy.

Or, even better, is there a way to issue a Rapid instruction which cause a WObj to be continuously offset in a defined direction based on encoder measured distance? This is actually they way this application was made in the past with Kawasaki robots.

Any smarter idea than wiring a general purpose digital output to the trigger input of CMT?

Many thanks,

Gabriel

lucavanin

Hi gea_gfantechi, 
Yes there is a signal to simulate the Trigger.

You can type:
PulseDO\High\PLength:=0.2,c1SoftSync;

If you want to manage a sequential trigger and you need to measure the distance between a trigger and other, you can use this code i've developed. (You need Multitasking)

EXAMPLE: Trig Foto and syncTrigger every 250mm

CONST dnum k_Maxc1Counts:=4294967295; !Max counts of encoder, youi can find in config data

CONST dnum k_CountsPerMeter:=48579; !Same of Process parameter
CONST num k_PhotoRatio:=250; !Distance between a trig and next

PERS num act_c1Counts_Vis; 
PERS num memo_c1Counts_Vis;

PROC TrigCmd()

        

   IF ((getDistance_Vis()>NumToDnum(k_PhotoRatio) AND c1NullSpeed=0 ) THEN

        ! Cmd Trigger to CTM

        PulseDO\High\PLength:=0.2,c1SoftSync;

    ENDIF

ENDPROC

FUNC dnum getDistance_Vis()

    VAR dnum l_n;

    act_c1Counts_Vis:=GInputDnum(c1Counts);

    memo_c1Counts_Vis:=GInputDnum(c1CntFromEnc);

    !Recalculate position if pass over 0 axis CNV1

    IF act_c1Counts_Vis<memo_c1Counts_Vis THEN

        memo_c1Counts_Vis:=(-1)*(k_Maxc1Counts-memo_c1Counts_Vis);

    ENDIF

    l_n:=((act_c1Counts_Vis-memo_c1Counts_Vis)*1000)/k_CountsPerMeter;

    RETURN l_n;

ENDFUNC


IF you want to store pulsencoder and take an ID of the trigger to use conveyor advanced tracking you can use GInputDnum(c1CntFromEnc).