Positioning Down Ramp - A Basic Positioning Function - Siemens Sinamics G120 CU240E Operating Instructions Manual

Functions
5.10 Technological functions
Parameter Description
P2350 =
...
P2354 =
...
P2355 =
...
r2260
P2261
r2262
r2266
r2272
r2273
r2294
For more information about this function, see function diagram 5100 in the List Manual.
5.10.4

Positioning down ramp - a basic positioning function

Description
In certain cases (e.g. when a conveyor belt is brought to a standstill), the belt may have to
travel a defined deceleration distance after shutdown regardless of the speed so that it
always stops in the same position.
Normally, the number of rotations that the motor requires to reach standstill depends on the
motor speed at the instant that it is switched-off. Using the "positioning down ramp" function,
the number of revolutions down to standstill can be defined independent of the speed. This is
realized by extending the ramp-down time of the motor after it has been switched-off so that
a specific number of motor revolutions is always reached. To realize this, the frequency
inverter has a positioning function that is sufficient for many applications.
The accuracy of this function can be increased by means of a motor encoder.
Table 5- 45
Parameter
P2480 = ...
P2481 = ...
P2482 = ...
P2484 = ...
P2488 = ...
P2487 = ...
For more information about this function, see the List Manual.
144
Enable signal for self-optimization
Monitoring time for self-optimization
Offset for self-optimization
Setpoint after ramp-function generator
Time constant for the setpoint filter
Filtered setpoint after ramp-function generator
Filtered feedback
Feedback after smoothing and function processing
Controller deviation (difference between setpoint and feedback)
Output value of controller
Parameters for the simple positioning function
Description
Control command for the positioning function
Example: When P2840 = 722.0, the positioning function is activated via digital input
0.
Gear ratio = P2481/P2482
Number of shaft revolutions at the gearbox output for one distance unit
Number of distance units until the end position
Additive compensation value for increasing accuracy
Frequency inverter
Operating Instructions, 08.10. 2008, t.b.d.