Percentage Acceleration Override (Acc Option) - Siemens SINUMERIK 840DE Programming Manual

Feedrate Control and Spindle Motion

7.10 Percentage acceleration override (ACC option)

Manual override in automatic mode
The manual override function in automatic mode for POS/A axes has two different effects
that are analogous to Jog functions.
1. Path override: FDA [ax] = 0
2. Velocity override FDA [ax] > 0
7.10 Percentage acceleration override (ACC option)
Function
In critical program sections, it may be necessary to limit the acceleration to below the
maximum values, e.g., to prevent mechanical vibrations from occurring.
You can use the programmable acceleration override to change the acceleration for each
path axis or spindle via a command in the NC program. The limit is effective for all types of
interpolation. The values defined in the machine data determine the 100% acceleration.
Programming
ACC[axis]=...
Or deactivate
ACC[axis]=100, program start, reset
Or
ACC[SPI(spindle)]=... or ACC(S...)
Parameters
ACC
SPI
Axis
7-30
The axis does not move. Handwheel impulses received for each IPO cycle are traversed
directionally and path-specifically. When the target position is achieved, the axis
decelerates.
The axis approaches the target position at the programmed axis speed. This enables
target position to be reached even without handwheel impulses. Pulses received for each
IPO cycle are converted to an accumulative change in the existing velocity. Impulses in
the traversing direction increase the velocity. Velocity is limited to the maximum axis
velocity MAX_AX_VELO. Impulses away from the traversing direction decrease the
velocity. The minimum velocity is 0.
Change in acceleration in percent for the specified path
axis or change in speed for the specified spindle.
Range of values: 1..200%, integers
Converts the spindle number into an axis identifier; the
transfer parameter must contain a valid spindle number.
The spindle identifiers SPI(...) and S... are identical in
terms of function.
Channel axis name of the path axis, e.g., with X
Programming Manual, 10.2004 Edition, 6FC5 298-7AB00-0BP1
Fundamentals