Hello All, I'm stuck with displaying continuous speed of moving cylinder on HMI. Basically what I want is car llike digital speedometer. When I stop the cylinder, speed must go to 0 instantly. I'm using S7-200, but it doesnt matter I guess. I tryed to calculate diference in position every 1 second, but the value keep jumping up and down. something to do with timing, cant solve it. The cylinder speed must be around 20mm/sec, I'm measuring the position with 4-20mA current comming fromwire potentiometer, there is no problem here. Thanks, Marwan