Link Axes; General Information - Siemens SINUMERIK 840D sl Function Manual

B3: Distributed systems - 840D sl only
3.2 NCU link
Programming
NCU1
A static synchronized action is used to write cyclically in the interpolation cycle the actual
current value $VA_CURR of axis 2 (NCU1/MA2) via the link variable $A_DLR[0] (REAL value)
to the first 8 bytes of the link variables memory:
Program code
IDS=1 WHENEVER TRUE DO $A_DLR[0]=$VA_CURR[MA2]
NCU2
With a static synchronized action, the transferred actual current value is read cyclically in the
interpolator cycle via link variable $A_DLR[0]. If the actual current value is greater than 23 A,
alarm 61000 is displayed.
Program code
IDS=1 WHEN $A_DLR[0] > 23.0 DO SETAL(61000)
3.2.3

Link axes

3.2.3.1

General information

A link axis is designated as a machine axis for which the setpoints are generated by a different
NCU than that to which the machine axis is physically connected. Link axes in conjunction with
axis containers (see Section "Axis container (Page 104)") permit in complex plants, such as
rotary indexing machines with several NCUs, the alternate use of machine axes of the NCU
of the link group.
The following figure shows as example an MA1 machine axis connected to the NCU1. The
MA2 machine axis is connected to the NCU2. The X and Z channel axes travel in interpolation
mode by a part program that runs in a channel of NCU1. The setpoints are generated in the
NCU1 interpolator. For machine axis MA1, they are forwarded to the position control of the
NCU1. For machine axis MA2, they are transferred via the NCU link to the position control of
the NCU2 and output there to the drive.
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Function Manual, 10/2015, 6FC5397-1BP40-5BA3
Extended Functions