Derivative-Action Times (Activation Time/Deactivation Time) - Siemens SIMOTION Function Manual

Time-based cams with a start position within the hysteresis range are not output (see figure
above).
Hysteresis range
The upper limit of the hysteresis range is set at 25% of the working range for a linear axis, and
25 % of the rotary axis range for a rotary axis. If you violate this maximum setting, an error
message is issued. In practice, a lower setting is used for the hysteresis range.
● Path-controlled output cam
● Time-based cam
● Time-based cam with maximum ON length
4.2.3.4

Derivative-action times (activation time/deactivation time)

To compensate for the switching times of digital outputs and connected switching elements,
or of propagation delays, it is possible to specify actuation times. Actuation times are calculated
from the sum of all delay times and can be specified separately for activation and deactivation
edges as an actuation time at the activation edge (activation time) or an actuation time at the
deactivation edge (deactivation time).
The activation/deactivation times of the output cam are dynamically compensated by means
of the derivative-action times. In this way, output cams are dynamically shifted depending on
the actual velocity.
For example, a valve that should open at 200°, with an activation time of 0.5 s
● Must be controlled at 195° at a velocity of 10°.
● Must be controlled at 190° at a velocity of 20°.
This dynamic shift takes place automatically by means of the TO camTrack.
Settings for the activation and deactivation times can contain positive or negative values.
A negative activation time must be entered if the output cam is to be switched before the
programmed start of the output cam.
Output Cams and Measuring Inputs
Function Manual, 04/2014
The hysteresis becomes active after direction reversal is detected. The output cam switches
off once the hysteresis has been left and the position is located outside of a defined output
cam.
The switching behavior of a time-based cam is determined by the ON duration, not by the
hysteresis. This means that an entered hysteresis range has no influence on the ON
duration of an output cam. It only has an influence on the switch-on time (start position).
The maximum ON length switches off the output cam once the hysteresis has been left and
the maximum ON length has been exceeded.
Note
If a time-based cam's start position lies within the hysteresis, it is not output.
Cam Track TO - Part II
4.2 TO Cam Track basics
79