This European Standard is applicable to safety-related electronic systems using for digital communication
purposes a transmission system which was not necessarily designed for safety-related applications and
– under the control of the designer and fixed during the lifetime, or
– partly unknown or not fixed, however unauthorised access can be excluded, or
– not under the control of the designer, and also unauthorised access has to be considered.
Both safety-related equipment and non safety-related equipment can be connected to the transmission
This standard gives the basic requirements needed to achieve safety-related communication between
safety-related equipment connected to the transmission system.
This European Standard is applicable to the safety requirement specification of the safety-related
equipment connected to the transmission system, in order to obtain the allocated safety integrity
Safety requirements are generally implemented in the safety-related equipment, designed according to
EN 50129. In certain cases these requirements may be implemented in other equipment of the
transmission system, as long as there is control by safety measures to meet the allocated safety integrity
The safety requirement specification is a precondition of the safety case of a safety-related electronic
system for which the required evidence is defined in EN 50129. Evidence of safety management and
quality management has to be taken from EN 50129. The communication-related requirements for
evidence of functional and technical safety are the subject of this standard.
This European Standard is not applicable to existing systems, which had already been accepted prior to
the release of this standard.
This European Standard does not specify
– the transmission system,
– equipment connected to the transmission system,
– solutions (e.g. for interoperability),
– which kind of data are safety-related and which are not.
A safety-related equipment connected through an open transmission system can be subjected to many
different IT security threats, against which an overall program has to be defined, encompassing
management, technical and operational aspects.
In this European Standard however, as far as IT security is concerned, only intentional attacks by means
of messages to safety-related applications are considered.
This European Standard does not cover general IT security issues and in particular it does not cover IT
security issues concerning
– ensuring confidentiality of safety-related information,
– preventing overloading of the transmission system.