B1: Continuouspath Mode, Exact Stop, LookAhead
3.3 Continuous-path mode
Basic Functions
Function Manual, 09/2011, 6FC5397-0BP40-2BA0
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Overload factor
The overload factor restricts step changes in the machine axis velocity at block ends. To ensure that the velocity
jump does not exceed the maximum load on the axis, the jump is derived from the acceleration of the axis.
The overload factor indicates the extent by which the acceleration of the machine axis
(MD32300 $MA_MAX_AX_ACCEL) may be exceeded for an IPO-cycle.
The velocity jump results as follows:
Velocity jump = axis acceleration * (overload factor-1) * interpolator cycle.
The overload factor is saved in the machine data:
MD32310 $MA_MAX_ACCEL_OVL_FACTOR (overload factor for axial velocity jumps)
Factor 1.0 means that only tangential transitions with finite velocity can be traversed. For all other transitions, the
velocity is reduced to zero by changing the setpoint. This behavior is equivalent to the function "Exact stop with
interpolator end". This is undesirable for continuouspath mode, so the factor must be set to greater than 1.0.
By setting the following machine data, the block transitions are rounded independent of the set overload factor
with G641/G642:
MD20490 $MC_IGNORE_OVL_FACTOR_FOR_ADIS
Activation/Deactivation
Continuous-path mode with a reduction in speed according to the overload factor can be activated in any NC part
program block by the modal command
G64
.
Selecting the exact stop which works on a block-by-block basis enables rounding to be interrupted (G9).
Continuous-path mode G64 can be deactivated by selecting:
• Modal exact stop G60
• Rounding G641, G642, G643, G644 or G645
Implicit continuouspath mode
If it is not possible to insert rounding blocks in continuouspath mode with rounding G641 due to the very short
block path lengths (e.g. zeroclocked blocks), the mode is switched over to continuouspath mode G64.
Note
For startup and installation, please note that the factor must be reduced if the machine is
likely to be subject to vibrations during angular block transitions and rounding is not to be
used.