Setting The Measuring Time To Evaluate Speed "0 - Siemens Sinamics S120 Function Manual

Basic functions
6.18 Tolerant encoder monitoring
6.18.10

Setting the measuring time to evaluate speed "0"

This function is only necessary for slow-speed drives (up to 40 rpm rated speed) in order to
be able to output actual speeds correctly close to 0. For a stationary drive, this prevents that
the I component of the speed controller slowly increases and the drive unnecessarily
establishes a torque.
Commissioning
● Enter the required measuring time in parameter p0453: A speed actual value of 0 is
6.18.11 Sliding averaging of the speed actual value
For slow-speed drives (< 40 rpm), when using standard encoders with a pulse number of
1024, a problem is encountered due to the fact that the same number of encoder pulses is
not available for every current controller clock cycle (for p0430.20 = 1: Speed calculation
without extrapolation, "Incremental difference"). The different number of encoder pulses
means that the speed actual value display jumps, although the encoder itself is rotating at a
constant speed.
Commissioning
● For sliding averaging, set parameter p0430.20 = 0 (edge time measurement).
● In parameter p4685, enter the number of current controller clock cycles over which the
284
output, if, within this time, no pulses are detected from the A/B track.
average value should be formed to calculate the speed. The averaging means that
individual incorrect pulses, depending on the number of specified clock cycles, are
smoothed.
Function Manual, (FH1), 01/2012, 6SL3097-4AB00-0BP2
Drive functions