Lenze 8400 StateLine - Manual (Page 959)

Lenze · 8400 StateLine · Reference manual · DMS 12.0 EN · 06/2014 · TD05/TD14
959
17 Function library
17.1 Function blocks
_ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _
Overlapping of blocking zones
If blocking zones overlap, the lowest and highest value of the overlapping zones form a new zone.
In this case, the status display (output wState or display parameter
C00634 ) only indicates one zone
(the lower of the two original zones).
Abutting blocking zones
If two blocking zones abut (e.g. 20 ... 30 % and 30 ... 40 %), the limit value between the two zones (in
this example 30 %) is also passed through.
The same applies to a limit range of 0 ... xx %. During zero crossing of the speed setpoint, "0" speed
is output as setpoint. It is possible to exclude "0" speed. However, in this case, the output speed will
remain on the upper limit value when the input setpoint becomes "0".

Tip!
As described above, the acceleration phase starts after the blocking zones have been
passed through. The ramp function generator integrated in the L_Nset function block
limits the progression of the speed. For this reason, the time values set for the integrated
ramp function generator should be as low as possible whereas the setpoint for the L_NSet
function block should be generated by a ramp function generator with higher time values
(e.g. L_MPot function block).
17.1.29.6 Ramp function generator for the main setpoint
The setpoint is now led via a ramp function generator with linear characteristic. The ramp function
generator converts setpoint step-changes at the input into a ramp.
[17-14] Acceleration and deceleration times
• t
ir
and t
if
are the desired times for changing between w1 and w2.
• S-ramps are possible by selecting S-ramp times.
• The t
ir
/t
if
values are converted into the required Ti times according to the following formula:
w1, w2 = change of the main setpoint as a function of t
ir
and t
if
RFG-OUT = output of the ramp function generator
RFG-OUT
100 %
w2
w1
t
0 %
t
ir
t
ir
T
ir
T
ir
T
ir
t
ir
100 %
w2 w1
–
----------------------- ⋅
=
T
if
t
if
100 %
w2 w1
–
----------------------- ⋅
=