VAA-2E2A-KE1-S/E2, VAA-2E2A-KE1P-S/E2
Appendix B
1
3
0
8
6
3
2
0
1
9
-0
4
25
2
The requirements of B must be
fulfilled and principles that are proven
for safety engineering purposes must
be used.
The safety function(s) must be
checked by the machine control at
suitable intervals.
NOTE
: What is suitable depends on
the application and the type of
machine.
■
The occurrence of a fault
can lead to the loss of
the safety function
between the test
intervals.
■
The loss of the safety
function is detected by
the test.
Via the
structure
3
The requirements of B must be
fulfilled and principles that are proven
for safety engineering purposes must
be used.
The control systems must be
designed such that:
■
An individual fault in the control
system does not lead to the loss
of the safety function, and
■
Whenever reasonably
practicable, individual faults are
detected.
■
When an individual fault
occurs, the safety
function is always
maintained.
■
Some, but not all, faults
are detected.
■
An accumulation of
undetected faults can
lead to the loss of the
safety function.
4
The requirements of B must be
fulfilled and principles that are proven
for safety engineering purposes must
be used.
The control systems must be
designed such that:
■
An individual fault in the control
system does not lead to the loss
of the safety function, and
■
The individual fault is detected
during or before the next time the
safety function is invoked. If this is
not possible, then an
accumulation of faults must not
lead to the loss of the safety
function.
When faults occur, the
safety function is always
maintained.
The faults are detected in
good time to prevent a loss
of the safety functions.
1)
The risk assessment indicates whether the complete or partial loss of the safety
function(s) due to the occurrence of faults is acceptable.
Category Summary of the requirement
System behavior
1)
Essential
principle to
achieve
safety
