Blinds and switch actuator RMG 8, blinds actuator JMG 4
and switch actuator module RME 8 - EIB
theben
As of: Apr-06 (Subject to change without notice)
Page 27 of 36
4.4.2 Determining the Slippage Compensation of the Drive Mechanisms
Refer to table 1-6: Expert parameters on the "Drives general" ETS tab
Due to the increased drive load, the asynchronous motor can perform lowering operations faster than
raising operations. In the field of electrical engineering, this effect is referred to as slippage.
To be able to calculate the exact position, this slip must be entered in the ETS on the "Drives general"
tab.
When observing the setting instructions and using high-quality blinds, identical height and angle
positions can be reached directly from any position without unnecessary travel times.
For correctly determining the slippage, the parameter Full running time "down" (see top of page) must
be set as accurately as possible.
Procedure:
•
Set the following parameters in the ETS on the "Drives general" tab:
•
Have the drive mechanism travel to the top position until the LED on the actuator goes out.
•
Lower the drive mechanism to the 20 % position using the Height [%] object.
•
Mark the position reached or measure the height.
•
Have the drive mechanism travel to the 80 % position using the Height [%] object.
•
Have the drive mechanism travel repeatedly between the 20 % and the 80 % positions using the
Height [%] object.
•
Finally, set the drive mechanism to the 20 % position again.
•
The difference in height / the offset between the marked position and the last position attained is
an indicator of the slippage.
The evaluation can be performed either by way of mathematics or empiricism:
•
In the case of the
empirical method
, the slippage is repeatedly adjusted and the drive mechanism
raised/lowered between the 20 % and 80 % positions (see procedure described above) until the
offset is minimized.
•
In the case of the
mathematical evaluation
, the offset is related to the single travel distance with
a percentage:
Slippage [%] = (L
v
*100) / (L
total
* n)
where
n
= the number of raising operations
L
v
= the measured offset
L
total
= the distance between the 20 % and 80 % positions
Example: travel distance from 20% to 80%: 200 cm, offset: 4.8 cm, number of raising operations from
80% to 20%: 3
