NORD Drivesystems BU0510 - Manual (Page 61)

5 Commissioning
BU 0510 GB-3911 Subject to technical alterations 61
After this a setpoint position in the vicinity of the actual position should be parameterised. If after being
enabled, the axis moves away form the position instead of towards it, the assignment between the direction of
rotation of the motor and the direction of rotation os the encoder is incorrect. The sign for the speed ratio
should then be changed.
If the detection of the actual position operates correctly, the position control can be optimised. In principle, with
an increase of the P amplification the axis becomes "harder", i.e. the deviation from the setpoint position
becomes smaller than with smaller amplifications.
The size of the P amplification which is set in P310 of the position control depends on the dynamic
characteristics of the system as a whole. In principle: the greater the masses and the smaller the friction if the
system, the greater is the tendency of the system to oscillate and the smaller is the maximum possible P
amplification. To determine the critical value, the amplification is increased until the drive unit oscillates about
the position (leaves the position and then approaches it again). The amplification should then be set to 0.5x to
0.7x this value.
For positioning applications with a subordinate speed control (P300 "Servo Mode"), for applications involving
large masses a setting which deviates from the standard setting of the speed control is usually to be
recommended. To parameterise the speed control - I - amplification in parameter P311, a value between 3%
and 5% has proved effective. In parameter P310 a speed control P amplification value of between 100% and
150% can be selected.