Lenze 8400 TopLine - Manual (Page 520)

8 Technology applications
8.5 TA "Switch-off positioning"
520
Lenze · 8400 TopLine · Reference manual · DMS 6.0 EN · 06/2014 · TD05/TD14
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System limits and exclusion criteria
They result from the non-compliance with the decision criteria.
• Compared to systems with speed feedback, the positioning and repeat accuracy is reduced.
• Due to the mechanical hardware limit switches, this concept is only applicable for systems with
only a few fixed positions. Changing the target position during the operation or the teaching is
not possible.
• If necessary, additional functions like manual jog or homing must be realised externally, e.g. via
a control.
• As the 8400 TopLine controller does not meet safety-related functions except STO (Safe Torque
Off), you must observe that all safety-related aspects are realised by the plant instructor.
• Especially in the case of an outdoor use or in wet areas, you must consider the corresponding
discharge currents when operated with a fault current circuit breaker.
• A table positioning or sequential positioning control is required for highly dynamic applications
and jerk-free traversing profiles which is available with the "HighLine" device version.
Related topics:
 Commissioning of the "Switch-off positioning" technology application ( 82)
Positioning accuracy at the motor
shaft
The positioning accuracy of the load
depends, among other things, on the
clearance and friction of the selected
mechanics and has to be determined
individually.
The ideal case is 5-10° at the motor
shaft.
Consider the influence of the motor
temperature.
In the case of a constant load, you can
assume a good repeat accuracy
during positioning. In the case of
variable loads, you must take
significant deviations into account.
5-10° at the motor shaft. As the
positioning is executed in a creeping
speed, a good repeat accuracy is
reached even for variable loads.
Speed setting range 1 : 50, based on 50Hz and M
n
1 : 50, based on 50Hz and M
n
Typical applications Switch-off positioning with constant
load, e.g. travelling drive, roll-up
door.
Switch-off positioning with variable
load, e.g. travelling drive, conveying
belt, hoists approaching a stop
position.
Criteria Switch-off positioning with constant
load
Switch-off positioning with variable
load