Different Position Control Cycles - Siemens SINUMERIK 840D sl Function Manual

B3: Several operator panels connected to several NCUs, distributed systems - only 840D sl
2.12 NCU link with different interpolation cycles
● Acceleration processes on the link axes are always output with the link cycle and are
● If high precision is required for the machining operation, the tool should not have contact
● It is only permissible to switch axis containers with rotating spindles on NCUs with IPO
2.12.2

Different position control cycles

The general solution described in Section "Diagram of general solution" also permits
different position control cycles for NCU-A/NCU-B and NCU-U as illustrated in the diagram
"Schematic example of a configuration with several NCUs and eccentric machining unit"
(Section "Diagram of general solution").
By setting the parameters as described below, you can improve the quality for some
controller types.
When interpolating, the different cycle times are detected in fine interpolation and in the
position control due to the different position control cycles; they are compensated for
internally by delaying the setpoints for the axes with the faster position control cycle.
Standard result
If the axis with the slower position control cycle is not accelerated or is only accelerated very
slowly, contour errors are largely avoided. However, contour errors will always occur when
accelerating, therefore accelerations should not take place while machining.
Special MD settings
In some cases, it may be necessary to be able to adapt the delay (see examples below).
This machine data was introduced for this purpose:
MD10065 $MN_POSCTRL_DESVAL_DELAY
It allows you to adapt the setpoint delay in the position controller for the entire NCU. You can
use positive and negative values. The set values (time in seconds, max. +/- 0.1sec) are
added to the automatically calculated values. See under "Information" below.
192
therefore not exactly synchronous with the axes physically connected to the fast NCU.
Therefore, it is only advisable to use this configuration with interpolating axes on NCUs
with different IPO cycles if you are machining with link axes that are only accelerated a
little or not at all. Thus the axes with high dynamic requirements must be physically
connected to the fast NCU.
with the workpiece during acceleration/deceleration of the axes. Otherwise contour
violations will result.
cycles that are equal to the link cycle. If it is possible to delay the container rotation,
switching is delayed until the spindle is motionless. Otherwise alarm 4019 is issued. Axis
container switching with motionless axes and spindles is also permissible on the faster
NCUs. (See "Axis container").
Function Manual, 09/2009, 6FC5397-1BP20-0BA0
Extended Functions