Rounding in case of division in the function block ARIT

Question:

What is the reason for rounding deviations in case of division in the function block ARITx?

Answer:

The division (mode = 4) in the function block ARIT is made only in integer values due to optimised time for calculations. Decimal codes are not considered, even not in temporary results.
The exact calculation is made as follows:

• Temporary result  =  IN1 * 164
• OUT = Temporary result / |IN2|

The values IN1, IN2, OUT are at the inputs and outputs in internal standardisation (16384 corresponds to 100 %). They are considered like this in the calculations. The factor 164 corresponds to the rounded factor 16384/100.

Tip:
Display codes of function block inputs often show the values in per cent, because the internal values are converted with factor 100/16384 only for the display. For some function blocks (FEVAN, FCNT, ...) the input values are displayed in the internal format.
In case of 9300 position controller the analog input signals of function block DISA can be displayed in per cent and in the internal format in the GDC menu 'Function blocks / DISA'.

URL for linking this AKB article: https://www.lenze.com/en-de/go/akb/20021169/1/