8 Application examples
11.03
8.4 Safe cams at the modulo limit
© Siemens AG 2003 All Rights Reserved
8-462
SINUMERIK 840D/SIMODRIVE 611 digital SINUMERIK Safety Integrated (FBSI) - Edition 11.03
Cam SN1+ must be greater than or equal to 0.099°.
SN1-
<
upper modulo value - SAFE_POS_TOL - SAFE_CAM_POS_TOL
SN1-
<
0° - 0.1° – 0.1°
SN1-
<
359.8°
Cam SN1- must be less than 359.8°.
When using the cam tolerance, it should be noted that the switching position of
the cam signal generated from switching signals SN1+ and SN1- varies
according to the traversing direction, the magnitude of the tolerance, and the
magnitude of the position deviations.
Example 2 (linear axis, pulse generation)
For a cam position of 100 mm and the following tolerances,
36942 SAFE_POS_TOL: 0.1mm (max. static deviation)
36940 SAFE_CAM_POS_TOL :
0.1mm
36936 SAFE_CAM_POS_PLUS[0]: 100
mm
(SN+)
36037 SAFE_CAM_POS_MINUS[0]: 99mm (SN-)
POSITION NCK at 0 mm :
0.000 mm
POSITION drive at 0 mm :
0.040 mm
(static deviations of actual values 0.040 mm)
then when the cam tolerance is active, the following switching characteristics
are obtained for the individual channels and the characteristics of the
synchronized signal.
Further, the following diagram shows how a pulse signal is generated from two
synchronized cam signals (schematic distances).
