D3-DA 3xx/x
Safety functions
Project engineering manual V1.07
75
© KEBA
Information
With deaktivated cross circuit test the system changes into safe state if a
test pulse, which does not meet the specification, occures.
Information
The failures "Short circuit output brake driver" and "Short circuit between
any cores in the motor supply cable" must be excluded by means of suit-
able wiring.
Testoutput assignment:
●
On the STO both test pulse must have a time offset.
●
On usage of redundant inputs different testoutputs must be used.
8.4
Recommended connection examples
The following chapter describes recommended examples for connecting
safety functions STO and SBC. In the following circuit examples it is a pre-
requisite that the switching elements used have safety-related approval or
are designed as per the required PL in accordance with EN ISO 13849-1 or
SIL in accordance with EN 61508 / EN 62061. In addition the following
points must be noted:
●
The safety regulations and EMC directives must be met
●
In relation to the failure exclusions assumed, reference is made to the
table in annex D of EN ISO 13849-2.
The examples shown in the following and their characteristic architecture de-
fine the allocation to a category in accordance with EN ISO 13849-1. The re-
sulting maximum possible performance levels in accordance with EN ISO
13849 continue to be dependent on the following factors related to the exter-
nal components:
●
Structure (single or redundant)
●
Detection of common cause failures (CCF)
●
Diagnostic coverage on demand (DC
avg
)
●
Time to the dangerous failure of a channel (MTTF
D
)
8.4.1
Example: STO and SBC control via safety control
The control of safety function STO is done via corresponding logical pro-
cessing of the safety control, whereby the safety function STO and SBC of
the single axis modules are controlled from the safety control via separate
outputs
