Siemens SIMOTION C230-2 Equipment Manual page 139

Reliability
The reliability of devices and components is maintained at the highest possible
level thanks to comprehensive and cost-effective measures implemented during
the development and manufacturing processes.
These include
S The selection of high-quality components
S Worst-case dimensioning of all circuits
S Systematic and computerized inspection of all components supplied
S Burning in of all LSI-circuits (e.g. processors, memories)
S Measures to prevent static discharge when handling MOS circuits
S Visual checks during various stages of manufacture
S Continuous heat testing at higher ambient temperatures for several days
S Thorough computerized final inspection
S Statistical analysis of all returned goods so that corrective measures can be
initiated immediately
S Monitoring the most important control components through online tests (watch-
dog for C230-2, etc.)
From the point of view of safety engineering, these procedures are considered to
be basic measures. They avoid or control the majority of faults that may occur.
The risk
Special safety standards must be applied to any system – and therefore to the situ-
ation as well – where, if a fault occurs, it may cause injury to persons or damage to
property. Special regulations specific to the system apply to such applications.
These cover the configuration of the control (e.g. VDE 0116 for heating plants).
In the case of electronic controls with safety implications, the measures that have
to be taken to avoid or contain faults must be based on the risk posed by the sys-
tem in which they are installed. In this respect, the basic measures listed above
are no longer adequate after the hazard exceeds a certain potential. Additional
measures (e.g. double redundancy, tests, checksums) for the control must be car-
ried out and certified (DIN VDE 0801).
E Siemens AG, 2003 All rights reserved
SIMOTION C230-2, 04.2003 Edition
Standards and Approvals
A-139