Siemens SINUMERIK 840D Description Of Functions page 467

11.03
Fig. 7-40 illustrates the inter-relationships at the machine and is used to explain
the appropriate configuring.
Fig. 8-11
The minus cam of a cam pair, for example (cams SN1+ - SN4 can all be used),
is set up in the machine data at the position immediately in front of the left safe
limit position (SE-). It must be ensured that SN- is passed if SE- is passed. This
means that the difference should be kept as low as possible (we recommend
0...0.1 mm).
A cam should be set up in the MD at the position directly behind the right safe
limit position.
The signal characteristics (of the interface signals – SGA) for the two
configured cams is shown in the diagram. These two signals can be used to
supply information to the hardware limit switch +/- interface signals.
© Siemens AG 2003 All Rights Reserved
SINUMERIK 840D/SIMODRIVE 611 digital SINUMERIK Safety Integrated (FBSI) - Edition 11.03
Traversing limits / monitoring
Mechanical traversing limit
SNx -
Traversing area (program)
Software limit switch -
SE-
Cam signal (SGA) SNx -
Example of retraction logic
8 Application examples
8.6 Direction detection when retracting from SE
Software limit switch +
Cam signal (SGA) SNx +
SNx +
SE+
SEFR_00.DSF
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