User manual

User Manual SCA-SS-70-10
ElectroCraft
®
E-Mail: [e-mail] www.electrocraft.com May 2009
28
6. Glossary
Offset
There are two distinct functions for the Offset-Potentiometer:
1. Levelling the position at which the motor stands still.
2. Selection of the Set Value. This task requires setting jumper J4 and opening
jumper J5. In any mode, this feature is available and offers the possibility of a
quick functional test.
It is advisable to begin the subsequent levelling procedure with an idle run of the motor.
However you cannot expect this calibration to be stable in the long term, because the motor
as well as the controller are always subject to thermal influences.
n max
Use this potentiometer to adapt the desired maximum speed to the amplitude of the present
set value.
Take care not to exceed meaningful limits. An exaggerated value may entail problems for
the control of the servo amplifier, making it impossible e.g. to line-up the system in speed
control operation under load.
Gain
The dynamical behaviour of the servo amplifier must be compatible to the particular
connected motor. The adjusting procedure is performed using the Gain potentiometer. A
bad adaptation (i.e. if the Gain value has been selected too high) can be easily recognized
by excessive motor vibration or noise. Consequential mechanical damages cannot be
excluded, furthermore an overtemperature situation may arise, due to high currents inside
the motor.
When setting the Gain value during a stop, the result most probably will have to be
accommodated one more time, because the dynamical reaction of the motor at a higher
speed will not be sufficient.
Always remember that this potentiometer does not only act on the gain itself, but also on the
frequency of the entire control loop.