Delem
V0208, 2.5
speed for the axis movement. As with the 1-speed axis, the parameter 'Stop time' (T) can be
used to improve positioning.
If the analog output is used for axis control, the parameters 'DC high speed' and 'DC low
speed' must be programmed at two different values. These values determine the voltage
levels at the analog output for the two different speed settings.
• One side positioning:
In the explanations above, the control systems used two-side positioning. So when moving
from high to low or vice versa, positioning takes place instantly.
In some cases, it is desired to have positioning only in one direction.
2.e
One side positioning is useful to overcome mechanical inaccuracies in the spindle. Final
positioning of the axis is always done from a higher to a lower position. So when the axis
moves from a high to a low position, positioning is done immediatly. When the axis moves
from a low to a high position, the axis will move to the overrun position (= programmed
position +OR). After that, the axis starts moving in the opposite direction and positioning takes
place.
When the difference between the new programmed position and the actual position is smaller
then BLS the axis is always moved to the overrun position first, also in case of two side
positioning.
Choosing 1-side or 2-side positioning is done with the parameter 'Spindle allowance'.
•AC brake
The control can be programmed to support a brake on the AC motor. This can be activated
with the parameter ‘AC-brake enable’. The motor brake is activated as soon as the speed
control is zero.
The brake signal is designed according to fail-safe principle: the signal is TRUE if the axis
must move, the signal is FALSE if no movement is allowed (the brake is active).
1.2.3. Unipolar system
Normally, the analog output can be used for movement control: positive voltage for one
direction, negative voltage for the other direction.
In a unipolar system the output voltage is always positive, the movement direction is indicated
by digital outputs.
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