Detailed Description
2.3 Continuous-path mode
Continuous-Path Mode, Exact Stop, LookAhead (B1)
2-8 Function Manual, 08/2005 Edition, 6FC5397-0BP10-0BA0
Acknowledgment outside of travel time
If, due to the programmed path length and the velocity of the block with auxiliary-function
output, the travel time is shorter than that set in machine data:
MD10110 PLC_CYCLE_TIME_AVERAGE
LookAhead deceleration is applied to the path velocity for the block, so that the duration of
the block corresponds to the time set.
If acknowledgment is not received within the time, the following prepared block cannot be
processed and the axes are braked to standstill with setpoint = 0 without considering the
acceleration limits.
Acknowledgment not received by end of block
If the acknowledgment is not received by the end of the block in long blocks in which the
velocity has not needed to be reduced on account of the PLC acknowledgment time, the
velocity is maintained until the end of the block and then reduced as described above.
Acknowledgment during braking
If the acknowledgment arrives while the axis is decelerating, the axis is not accelerated back
up to the requested velocity.
MD10110
Machine data:
MD10110 PLC_CYCLE_TIME_AVERAGE
is not evaluated.
2.3.2 Velocity reduction according to overload factor
Velocity reduction according to overload factor
The function lowers the path velocity in continuous-path mode until the non-tangential block
transition can be traversed in one interpolation cycle while respecting the deceleration limit
and taking and overload factor into account.
With the reduction in velocity, axial jumps in velocity are produced with a non-tangential
contour at the block transition. These jumps in velocity are also performed by the coupled
motion synchronized axes. The jump in velocity prevents the path velocity dropping to zero.
This jump is performed if the axial velocity was reduced with the axial acceleration to a
velocity from which the new setpoint can be reached with the jump. The magnitude of the
setpoint jump can be limited using an overload factor. Because the magnitude of the jump is
axial, the minimum jump of the path axes which are active during the block change is
considered during block transition. With a practically tangential block transition, the path
velocity is not reduced if the permissible axial accelerations are not exceeded. In this way,
very small angular changes in the contour can be overtraveled directly.
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