Davis_1377
Member
I am measuring 12v from 0-10v analog input with a voltage divider, 2 resistors that are 20m Ohm (also tried it with 2k Ohm resistors). I get a accurate reading but when the analog input gets a certain voltage there is a odd fluctuation in the reading thats higher and lower than the correct value. I have tried different inputs on the card, different resistors even a potentiometer to adjust voltage from a 9v battery. Ive eliminated all possible nearby interference. Nothing I try seems to affect the signal. I dont believe in a programming issue as other voltages are correct. Filtering does not help everyway Ive tried. The fluctuation pattern is too perfect but not always and is higher and lower than the correct value. My PLC is DL205 with 260 CPU and F2-04AD-2 Analog Input. Attached is the analog signal and steady voltage input. Any help is greatly appreciated.