Vertical Load

Valid for S300, S700

Suspended loads pose quite a challenge to the electric drive. Below is important information that should be considered during project planning.

Any vertically moved loads or loads under spring tension may move unintentionally when the Enable stage is engaged.

Cause: In order to actively (the servo amplifier output assists the motor) maintain the load's position, the current regulator or the speed/position regulator must detect a deviation. Only once a deviation is detected can the current regulator's corrected variable be determined, resulting in the motor's holding torque. An optimized parameter setting (IEXTT parameters, current pre-control) can minimize these effects.

Start the DriveGUI setup software, select menu item 'terminal':

PFB shows the current position when in enabled state.

Use command K to stop the output and apply the break, as soon as the value of speed V sits below the standstill threshold VEL0.
Without any further settings, the position changes once the axle is enabled (EN). In this example = 287 position units. 
Use command I to reach the built up holding current, I=0.252mA.

This holding current is the required value for the IEXTT Parameter.
Input this determined value into the IEXTT parameter and save the data.
Close and enable the output stage once more; you should see almost no position offset, the load should be stable and no longer slides down. Check for movement (correct current) by starting up.

If movement persists:
Downwards movement --> increase IEXTT value
Upwards movement  --> reduce IEXTT value

The optimal setting has been achieved if the load is sustained and no positional movement occurs when enabling the Motor.

You can also record movement in the DriveGUI oscilloscope and save it as a CSV file for Analysis.

Input the following user-defined variables for the channels:  EN_P_I , EN_BRAKE_I , PFB and ICMD .
Set trigger signal to EN_P_I, positive trigger edge, trigger level to 1 at 25%.