11.03
8 Application examples
8.4 Safe cams at the modulo limit
© Siemens AG 2003 All Rights Reserved
SINUMERIK 840D/SIMODRIVE 611 digital SINUMERIK Safety Integrated (FBSI) - Edition 11.03
8-461
NCK
Q1
K1
Q2
+24 V
NCK
I1
Fig. 8-11
Signal generation for modulo cam 3
In this case, the OR operation is implemented by wiring the two outputs to a
contactor whose contacts can be used for further processing or can be logically
combined with other signals.
The signals are logically combined in the PLC in the usual manner:
UN DB3x.DBX109.0
//
SN1+
O DB3x.DBX109.1
//
SN1-
=
M2.0 // Position detection 0°
Cam synchronization can also be activated for position monitoring, in order that
the two safety channels are switched in synchronism (see also Section 3.7).
This synchronization is necessary if the safe cam signals are to be processed
in the SPL.
Consideration should be given to conditions which can affect the parameter
settings and the effect of synchronization on position detection.
The position of the safe cams at the modulo limit must be aligned to the
selected cam tolerance. The calculations shown here are also performed by the
Safety Integrated system and, in the event of a parameter error, Alarm:
27033 Parameterization of machine data 36936/36937 [0-3] invalid
is displayed.
The following machine data is assumed for the calculations below:
36942 SAFE_POS_TOL :
0.1mm
36940 SAFE_CAM_TOL :
0.1mm
Example 1 (rotary axes)
SN1+
≥
lower modulo value + SAFE_POS_TOL
SN1+
≥
359.999° + 0.1°
SN1+
≥
0.099°
Cam synchronization