Kataeb
Member
I need to check an axis actual travel position, and to compare it to the master travel position.
To do this I have to multiply the axis travel position by the strange ratio of 36/21 , and then add the result to the total calculated value.
This happens at every scan of the plc program, and so I slowly lose the digits after the 7th one. After some time, I notice some differences that are coming from these calculations.
The used Rockwell plc has 7 digits precision for real data type.
36 / 21 = 1.7142857 . . .
To do this I have to multiply the axis travel position by the strange ratio of 36/21 , and then add the result to the total calculated value.
This happens at every scan of the plc program, and so I slowly lose the digits after the 7th one. After some time, I notice some differences that are coming from these calculations.
The used Rockwell plc has 7 digits precision for real data type.
36 / 21 = 1.7142857 . . .