Controlling the safety functions
5.2 Control of "STO" and "SS1" via terminal module for option K82
Safety Integrated
Function Manual, 08/2023, A5E03264275A
43
Recommended application
This option is used when the following requirements apply:
• Control is realized with electrical isolation in a voltage range 24 V DC/AC.
• Using non-shielded control lines which are longer than 30 m.
• The devices are deployed in plants dispersed over a wide area (no ideal equipotential
bonding).
Principle of operation
Two independent channels of the integrated safety function are controlled via relays (-K41,
-K42).
Relay -K41 controls the signal at the Control Unit that is necessary for the safety function and
relay -K42, the corresponding signal at the Motor Module.
The selection and deselection must be simultaneous. The time delay that is unavoidable due
to mechanical switching operations, for example, can be adapted via parameters. p9650
specifies the tolerance time within which selection/deselection of the two monitoring
channels must take place to be considered as "simultaneous".
The circuit is structured so that it is protected against wire break, i.e. if the relay's control
voltage fails then the safety function is active.
A feedback signal is not part of the safety concept.
Note
The feedback signal is not necessary to comply with standard ISO
13849-1 Cat. 3 PL d and
The selection of the safety function must be performed in two channels. A switch according
to ISO 13850, positive opening according to IEC 60947-5-1 or a certified safety control must
be used as actuating element.
Failure of the safety functions as a result of an unsuitable actuating element
An unsuitable actuating element may cause the safety function to fail which can result in
death or serious injury.
• Select the correct actuating element to comply with the standard to be complied with
(ISO 13849-1 Cat. 3 PL d or IEC 61508 SIL 2) for the complete system.
Forced checking procedure
The maximum value for the forced checking procedure interval when using option K82 is
12 months (8760 h).
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