Festo Контроллер позиционирования CPX-CMAX - Manual (Page 125)

3. Drive functions
3−63
Festo P.BE−CPX−CMA X−CONTROL−EN en 0908NH
Defined switching conditions in the CMAX
Value Condition Description
0 ć No switch.
1 ć Reserved
2 Position The preselected value is interĆ
preted as the position value
1.
The switch happens as soon as
the current actual position exĆ
ceeds the preselected value in the
direction of travel
2.
As there is no need to stop, the
drive reaches its target position
quicker.
2
1
MC
Speed
Position
3 Force The preselected value is interĆ
preted as the force value
1.
There is a switch when the current
actual force has exceeded the
preselected value
2 .
The first command doesn’t
necessarily have to be a force
command. Example: Slow posiĆ
tioning to the end point. When
the force threshold has been
reached, force control is switched
to.
2
1
MC
Speed
Force
Notes:
Ĉ The meaning of exceed" is derived from the starting and target values of the
force (analogously to positioning).
Ĉ When switching from a positioning task: Besides the expected counteracting
force, the force for accelerating the mass and the friction of the system also
determine the current force value, and with this, the switching position.
Therefore, only a small degree of switching position reproducibility is to be
expected in this case. Only when the axis is positioned against a spring force,
for example, and the force which occurs here is more than twice the frictional
forces, including the acceleration force, does the switch result in more−or−
less reproducible behaviour.