CSN EN IEC 61158-4-4 ed. 4

CSN EN IEC 61158-4-4 ed. 4 The data-link layer provides basic time-critical messaging communications between devices in an automation environment. This protocol provides a means of connecting devices through a partial mesh network, such that most failures of an interconnection between two devices can be circumvented. In common practice the devices are interconnected in a non-redundant hierarchical manner reflecting application needs.
Original English text of CSN EN Standard.
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