Siemens SINUMERIK 840D Description Of Functions page 20

1 Short Description
All safety-relevant errors in the system always cause potentially hazardous
Mastering extreme
conditions movement to be brought to a standstill or the motor to be disconnected from the
professionally power supply.
The necessary disconnection of the converter from the motor is contactless and
can be initiated on an axis-for-axis basis with a very short response time. The
drive DC link does not have to be discharged.
The drives are brought to a standstill in the optimum way, adapted to the
operating conditions of the machine. For example, each axis can be brought to
a standstill separately in the setting-up mode when the protective door is open.
This means a high degree of protection for the personnel during set-up and
additional protection of the machine, tool and workpiece in the automatic mode.
Activation of external braking mechanisms supplements the integrated
functions and results in the shortest possible braking distance with safe
standstill. External braking mechanisms might be:
•
•
Scope of functions
The safety functions are available in all modes and can communicate with the
process using safety-related input/output signals.
•
•
•
1-20
SINUMERIK 840D/SIMODRIVE 611 digital SINUMERIK Safety Integrated (FBSI) - Edition 11.03
Acquisition
Bus
PLC
I/O
computer
Type 3
Bus
NC
I/O
computer
Type 1
incremental
Signal
Drive
encoder
or absolute
computer
Type 2
An external mechanical brake
A holding or operational brake
An external electrical brake
Armature short-circuiting or eddy-current brake.
Safe standstill
A monitoring function or sensor (e.g. light barrier) responds and brings a
moving drive to a standstill.
Safe operating stop (SBH)
Monitors the drives during standstill within a settable tolerance window.
The drives remain fully functional in closed-loop position control.
Safe standstill (SH)
Drive pulses are cancelled so that the energy feed is safely and
electronically disconnected.
Evaluation Reaction
Cross-check of
data and results
Cross-check of
Pulse disable
data and results
paths
© Siemens AG 2003 All Rights Reserved
11.03
Feedback singals
Drive
power
section
Feedback singals