Example: Lightbus drive

With a Lightbus drive, the parameter VUNIT is assigned the value 1 in the default factory parameter definition. This means that the specified velocity for the drive takes place in revolutions per minute (rpm).

Step 1 of 3:

According to the manufacturer’s documentation, the conversion factor between revolutions per minute and the command value transferred in the cyclic telegram is:

The value 140 (rounded) must be output to rotate the motor at a speed of one revolution per minute.

Step 2 of 3:

To reach a speed of 1 m/min, the following motor speed is required at a spindle pitch of 5 mm and a gear ratio of i = 1:1

Step 3 of 3:

At a velocity scaling factor f, the output velocity command value for 1 m/min is:

This results in the following value:

Alternatively, multi_gain can be calculated using the following equation:

where I_u is the number of encoder increments per motor revolution. For a Lightbus drive, this results is 65536 increments per revolution.

A spindle pitch of 5 mm/revolution and 65536 increments per revolution result in wegauf_z=65536 and wegauf_n=50000.

The possible values for P-AXIS-00129 and P-AXIS-00128 would then be: