Lenze ETC Motion Control - Manual (Page 196)

Machine constants
Software configuration
MK_LAH_GRENZWINKEL
4
4.3
4.3.9
l
196 EDSTCXN EN 2.0
4.3.9 MK_LAH_GRENZWINKEL
This machine constant limits the Look Ahead function (G60) to a defined
angle range. During this process, the system switches automatically to exact
positioning on non−tangential block transitions, on which the transition
angle is larger than the value of this MC.
This is to ensure that these corners in the profile can be precisely approached
even when Look Ahead is switched on by forcing the speed on the corner
down to 0.
The speed on the block transitions on which the transition angle is less the
value of this MC, is not reduced to 0 but only as defined in
MK_KONTURFEHLER.
Value Meaning
0 If there is even a slight change of direction, this will lead to a standstill at the block
transition.
15 Only a change of direction in excess of 15
°
will lead to a standstill.
45 Only a change of direction in excess of 45 ° lead to a standstill (default).
180 Special case: no speed reduction at block transitions.
Permitted values for this MC range between 0 and 180
°
. Please bear in mind
that the special case 180
°
may lead to acceleration jumps at the block
transitions and thus to incorrect SW limit switch messages in the look−ahead
SW limit switch function (MK_SW_ENDS_MIT_RAMPE = 2).
4.3.10 MK_RADIUS_B_BEWERTUNG
This machine constant is a factor, which can be used to affect the maximum
traversing speed when machining curves. The control limits the speed when
machining circles depending on the circle radius and the permissible path
speed per time unit (jerk) as follows:
3 2 K/T B R = V
⋅ ⋅
max
V
max:
max. speed on the circular arc [mm/s]
R: radius of the circular arc [mm]
B: Set path acceleration (MK_BAHNBESCHL, G201) [mm/s 2 ]
T: time constant for the permissible acceleration increase
(MK_T_BAHNBESCHL) [s]
K: Value of MK_RADIUS_B_BEWERTUNG
This MC is thus an evaluation factor for the permissible jerk on circular arcs.
It can be used to correct the speed limit for small radii upwards or
downwards.