09.2008 Functions
Siemens AG 6SE7087-6QX70 (Version AK)
SIMOVERT MASTERDRIVES Compendium Motion Control 7-11
The ramp-function generator tracking (limiting) always has an effect, i.e.
even if the RFG is blocked. The positive limiting value should always be
greater than the negative limiting value, otherwise the limitation cannot
be correctly calculated. If the positive limiting value is negative, the out-
put is limited to this negative value even if the RFG has been blocked!
Bridging of the ramp-function generator has the following effect:
♦ The output value y is equal to the input value x, irrespective of the
commands ramp down and stop.
♦ In the case of quick stop, however, the quick-stop time has an
effect.
7.2.2 Technology controller
The following calculating times apply to the technology controller:
♦ PI controller with Kp adaptation: 38 µsec
♦ PID controller with Kp adaptation and smoothing: 48 µsec
♦ With all (droop, precontrol, RFG at output): 58 µsec
Due to negative factor, a sign reversal is possible!
♦ The I component is always set, irrespective of whether the controller
is blocked or enabled.
♦ If the controller is blocked, the controller output is always zero, even
when the I component is set
♦ When Tn = 0, the I component is deleted, the effect is equal to
Tn = ∞
♦ Tracking of the I component only occurs when the output is limited
(B0555 = 1) and Tn <> 0 and the controller is enabled and the
I component is not set.
Blocking of the technology controller results in the following:
♦ The limiting ramp-function generators are reset
♦ The setpoint, actual value, smoothing and controller input are
calculated
♦ The D component is calculated
♦ Droop and precontrol are added
♦ P component and controller output are zero
♦ No setting of the I component => I component is deleted
♦ The output limitation is calculated (with B+ = B- = 0)
♦ No sub-sampling, i.e. each value is used
♦ With a smoothing time of zero, the smoothing element is set to the
input value
♦ Smoothing time : scan time < 500
=> max. 1 % error in smoothing time
♦ Smoothing time : scan time = 3000
=> max. 10 % error in smoothing time
♦ Smoothing time : scan time > 20000
=> should not be set
RFG tracking
RFG bridging
Calculating time
Kp adaptation
I component
Controller block
Smoothing