Siemens SINUMERIK 840D sl Commissioning Manual page 142

NCK start-up
10.5 Parameterize axis data
Acceleration
In the following machine data machine axes are accelerated and decelerated with the values
entered.
● MD32300 MAX_AX_ACCEL (Axis acceleration)
This value should allow the axes to be accelerated and positioned fast and accurately, while
ensuring that the machine is not loaded unduly.
Checking the acceleration
The sign of a properly adjusted acceleration of a machine axis is acceleration and
positioning free from overshoot at rapid traverse rate and maximum load (max. external
moment of inertia).
After the acceleration has been entered, the axis is traversed rapidly and the actual current
values and current setpoint are recorded.
This recording shows whether the drive reaches the current limit. Here, the current limit can
be reached for a short time.
The current must be well below the current limit, however, before the rapid traverse velocity
or the final position is reached.
Load changes during the machining should not result in the current limit being reached, as
they may result in contour errors. For this reason, the acceleration value should be a little bit
less than the maximum acceleration value.
Machine axes can have different acceleration values, even if they interpolate with each
other.
Jerk
For jerk, the following should be noted:
● For indexing program instructions (SOFT), the maximum jerk must be set in the following
● For JOG and positioning axes the following machine data should be supplemented:
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machine data:
– MD32431 MAX_AX_JERK (maximum jerk)
– MD 32420 JOG_AND_POS_JERK_ENABLE
– MD 32430 JOG_AND_POS_MAX_JERK
Commissioning Manual, 07/2007, 6FC5397-2AP10-3BA0
IBN CNC: NCK, PLC, drive