Manual
ibaMS4xUCO
80
Issue 1.5
11.4
Tips
The following calculations require the number of pulses of the encoder (pulses per rev-
olution). This is specified in the data sheet of the encoder.
The specified number of pulses, however, always refers to a measurement in "direct
mode".
If the measurement is carried out in "quadrature mode" (higher accuracy), a factor of 4
for the number of pulses must be taken into account in all calculations. Otherwise the
result of the calculations below is in "quadrature mode" either too large or too small by a
factor of 4.
11.4.1
Speed calculation
With incremental encoders, a measured frequency may be converted into speed using
a virtual module in ibaPDA. For information about creation and handling of virtual mod-
ules, refer to the ibaPDA manual.
This is the expression for calculating the speed in a virtual module:
Revolutions/second = ([measured frequency] / <pulses per revolution>)
or
Revolutions/minute = ([measured frequency] / <pulses per revolution>) *
60
11.4.2
Distance calculation
With incremental encoders, measured pulses can be converted into a distance using a
virtual module in ibaPDA. For information about creation and handling of virtual modules,
refer to the ibaPDA manual.
If a distance is to be calculated using the number of pulses, not only the pulses per
revolution of the encoder must be known, but also the radius or circumference of the
measuring wheel.
<pulses per revolution>
<circumference of the measuring wheel> = π * < diameter of the measuring
wheel>
The expression for the calculation is as follows:
Distance per pulse = <circumference of the measuring wheel> / < pulses
per revolution>
Or
Distance = (circumference of the measuring wheel> * <pulses>) / <pulses
per revolution>
