Siemens SIMATIC FM 452, Руководство пользователя

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Basics of Cam Control
2-3
FM 452 Electronic Cam Controller
C79000-G7076-C452-04
Table 2-1 Definition and Switching of the Two Cam Types
Distance Cam Time Cam
Representation
Cam end Cam start
Cam length
s
Activation
time
Cam start Cam end
s
Parameter
Settings
The following parameters are required:
•
Cam start
•
Cam end
•
Activation direction
•
Lead time
The following parameters are required:
•
Cam start
•
Activation time
•
Activation direction
•
Lead time
Activation
Direction
Two activation directions are possible:
•
Positive: The cam is activated at the
cam start when the axis is moving in
the direction of increasing actual
values.
•
Negative: The cam is activated at the
cam end when the axis is moving in
the direction of decreasing actual
values.
You can set both activation directions at
the same time.
Two activation directions are possible:
•
Positive: The cam is activated at the
cam start when the axis is moving in
the direction of increasing actual
values.
•
Negative: The cam is activated at the
cam start when the axis is moving in
the direction of decreasing actual
values.
You can set both activation directions at
the same time.
Activation The cam is activated:
•
At the cam start when the axis is
moving in a positive direction and the
positive activation direction is set.
•
At the cam end when the axis is
moving in a negative direction and
the negative activation direction is
set.
•
The actual value is within the range
of the cam.
The cam is activated:
•
At the cam start when the direction of
movement of the axis matches the
activation direction.
After it has been activated, the full cam
activation time elapses even if the
direction of movement of the axis
changes after the cam is activated. If the
cam start is passed again during this
time, the cam is not retriggered.
Deactivation The cam is deactivated when:
•
The selected distance has been
traveled,
•
The activation direction is opposite to
the direction of movement of the axis
and no hysteresis is set,
•
The actual value is no longer within
the range of the cam.
The cam is deactivated when the
selected time has expired.
Active length The active length of the cam is defined
by the cam start and cam end.
Cam start and cam end belong to the
active section of the cam.
The active length of the cam depends on
the speed at which the axis travels while
the cam is active.
On Time The on time of the cam depends on the
speed at which the axis travels the
active length of the cam. The on time of the cam is selected with
the activation time.