Hw/Sw Limit Switches Of Following Drive - Siemens SINUMERIK 840C Installation Instructions Manual

08.96

12.18.11.5 HW/SW limit switches of following drive

If the following axis traverses beyond an HW or SW limit switch, then an internal limit switch is
simulated for all leading axes depending on the sign of K
leading axis had traversed into contact with an SW limit switch. Accordingly, the channels of
the leading axes (and thus also of the other axes interpolating with the leading axes) are also
stopped. The leading axes can be traversed away from the limit switch (ensure correct
direction of traversal).
If the following axis traverses onto the prelimit switch, then the velocity of the leading axes
which are moving the following axis towards the limit switch is reduced depending on the sign
of K (simulated prelimit switch for leading axes).
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Leading spindles are stopped (regardless of their rotational direction) as soon as the following
axis reaches a HW/SW limit switch. The spindle cannot be traversed in any direction as long
as the following axis is situated behind a limit switch.
If the leading spindle is being traversed by oscillation or alignment, then the oscillation/
alignment function must be aborted (cancellation of interface signals) once the following axis
has been traversed away from the limit switch before the spindle can be restarted.
The following axis always traverses beyond the limit switches by a few increments because the
following axis stop command cannot be released until the limit switch is reached.
Note:
If a following axis is driven with a leading axis that is moved in follow-up mode using the actual
value link, the following axis cannot be stopped if it overshoots the SW limit switch.
Remedy:
• Stop the leading axis (e.g. external conveyor belt)
• Deactivate the link via the hardware limit switch
From SW 5.6, the function "Dyn. SW limit switches for following axes"
can be used if the path velocity is to be reduced and the following axis
must not traverse beyond the software limit switches
(see Sect. Dyn. SW limit switches for following axes).
© Siemens AG 1992 All Rights Reserved
SINUMERIK 840C (IA)
. The effect is the same as if every
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6FC5197- AA50
12 Functional Descriptions
12.18.11 GI monitors
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