Siemens SINUMERIK 840D Description Of Functions page 128

3 Safety-Related Functions
3.9 Safety-related input/output signals (SGE/SGA)
Processing in the drive monitoring channel
Safety functions can be selected/de-selected independently of the NC
operating mode
Differences between the active SGEs in the monitoring channels are detected
by the crosswise data comparison.
Two-channel A two-channel structure (see Fig. 3-21 "NCK and drive monitoring channels") is
processing of I/O provided for the input/output and processing of safety-relevant input/output
signals for NC and signals. All requests and checkback signals relating to safety-relevant functions
drive must be entered or retrieved through 2-channels via both monitoring channels.
Fig. 3-27
For the NCK monitoring channel, the signals are input and output via the
NCK I/O devices, processed by the NCK logic operations block and mapped in
the SGE/SGA interface.
The signals from the drive monitoring channel are input/output via the PLC I/O
devices, processed by the PLC user program and transferred to the drive or the
PLC via the NC/PLC interface.
3-128
SINUMERIK 840D/SIMODRIVE 611 digital SINUMERIK Safety Integrated (FBSI) - Edition 11.03
NCK NCK signal-
I/O devices processing
HW NCK
inputs/ signal
out- proces-
puts sing
NCK monitoring channel
Machine
Drive monitoring channel
HW- PLC
Inputs/ signal
out- proces-
puts sing
PLC PLC signal
I/O devices processing
Process
NCK and drive monitoring channels
Interface
Comparator
NCK
SGE/SGAs
Data
Result and data
cross-check
Comparator
NC/PLC
interface
Data
Axis/spindle
DB
Interface
System
SGESGA03.DSF
© Siemens AG 2003 All Rights Reserved
11.03