×
Siemens Industry Online Support
Siemens AG
Entry type: FAQ Entry ID: 35444114, Entry date: 09/28/2018
(4)
Rate

Diagnostic coverage level to be specified and achievable safety integrity level for subsystems or SRP/CS with electromechanical components

  • Entry
  • Associated product(s)
This entry provides information on the diagnostic coverage level.

QUESTION:

Which diagnostic coverage level can typically be specified for subsystems or SRP/CS with electromechanical components and which safety integrity level can then be achieved?

 

 

ANSWER:

Diagnostic coverage level to be specified for subsystems or SRP/CS with electromechanical components and achievable safety integrity level SIL in accordance with IEC 62061 or Performance Level PL in accordance with ISO 13849-1.


With DC
99%, SIL 3 in accordance with IEC 62061 or PL e in accordance with ISO 13849-1 can be achieved as a maximum if

 

  • Two components that are monitored for discrepancy and cross circuit are used and are tested once a month.
    Example:
    Two position switches or two contactors that are monitored by means of mirror contacts, at the latest when switched on again,  and are tested once a month.

 

  • One component is monitored electrically via two channels for discrepancy and cross circuit.
    Example:
    An emergency stop command device (this is also true if multiple emergency stop command devices are connected electrically in series, because regular and simultaneous activation of multiple emergency stop command devices can be excluded).

 

 

With DC 90%, SIL 2 in accordance with IEC 62061 or PL d in accordance with ISO 13849-1 can be achieved as a maximum if

 

  • One component is monitored electrically via two channels for discrepancy and cross circuit and is tested once a year.
    Example:
    A position switch with separate actuator and error exclusion actuator break.

 

 

With DC 60%, SIL 2 in accordance with IEC 62061 or PL d in accordance with ISO 13849-1 can be achieved as a maximum if

 

  • Multiple components that are connected electrically in series are monitored for discrepancy and cross circuit and are tested once a year.
    Example:
    A total of six position switches (i.e. 3 x protective door monitoring), whereby two position switches are required for each protective door monitoring.
    Restriction regarding achievable SIL 2 or PL d:
    The statement above only applies when it can be excluded that more than one door can be opened at the same time!

 

 

You can find additional information on the diagnostic coverage level in the corresponding standards, ISO 13849-1 and IEC 62061.

Security information
In order to protect technical infrastructures, systems, machines and networks against cyber threats, it is necessary to implement – and continuously maintain – a holistic, state-of-the-art IT security concept. Siemens’ products and solutions constitute one element of such a concept. For more information about cyber security, please visit
http://www.siemens.com/industrialsecurity.
Support to the statistics
With this function the IDs found are listed according to number (format .txt).

Generate list
Copy URL
Display page in new design
mySupport Cockpit
Related links