Dynamic $OV_PRO [SOLVED]

Hi there,
I'm trying to implement a dynamic control for the $OV_PRO. I'm cutting with a circular saw and I would like to tune automatically $OV_PRO value while the saw gets deep into the material in order to keep spindle RPM constant especially during the initial immersion. This is my SPS by now, but it gives me an error during execution that says that "Value assignment is inadmissible".

[...]
REAL RPM_DIF  
[...]


;---------DYNAMIC OV_PRO


    IF HSD_SPEED_IN > 100 THEN                                                           ;HSD_SPEED_IN is the speed read by the sensor
      RPM_DIF = HSD_SPEED_IN / HSD_SPEED_SET                                  ;HSD_SPEED_SET is the speed set by the program
      $OV_PRO = (100-(99*$ANIN[1]))*RPM_DIF
    ELSE
      RPM_DIF=1                   ;
      $OV_PRO=100-(99*$ANIN[1])   ; BASIC OV_PRO CONTROL                ;$ANIN[1] is the value of a potentiometer to control $OV_PRO from the remote pendant
    ENDIF

I found this old post, so I guess I'm not too far from the solution.

https://www.robot-forum.com/robotforum/kuk…84495/#msg84495

Maybe someone has some suggestion?
Cheers,
Marco

Quote from Martin84

I think you should create some variable and then pass this results to $ ov_pro. you must also remember that $ ov_pro can have a value from 0 to 100 .

$OV_PRO=100-(99*$ANIN[1]) alone works perfectly, my $ANIN[1] values are remapped from 0 to 1. I do have my RPM_DIF declared and initialised in my SPS.

Quote from Martin84

Type int

I don't get it. OV_PRO is INT already and the basic function $OV_PRO=100-(99*$ANIN[1]) without the RPM addition works fine since as it is declared as int it cuts off decimals. RPM_DIF must be real, smaller than 1 to get the $OV_PRO reduction in addition to the reduction from the potentiometer. For example: $OV_PRO = 100, Potentiometer at 50% which means $ANIN[1] = 0.5 then I Have $OV_PRO = 50. Additionally, if during milling I get HSD_SPEED_IN = 800 while HSD_SPEED_SET = 1000 then 800/1000= 0.8, which means 50(OV_PRO FROM PREVIOUS REDUCTION) x 0.8 = 40 as final ov_pro value.
Hence, ov_pro should self-adjust all the time as the saw finds more resistance while cutting as to compensate the feed rate and avoid rpm drops.

SOLVED. If this is gonna be useful for someone else, the problem was that the result of HSD_SPEED_IN / HSD_SPEED_SET was sometimes >1 due to speed little variation above the set value. Then the $OV_PRO final value was getting bigger then 100 and giving the error.