BS EN IEC 61158-4-2:2019

The data-link layer provides basic time-critical messaging communications between devices in an automation environment.

This protocol provides communication opportunities to all participating data-link entities, sequentially and in a cyclic synchronous manner. Foreground scheduled access is available for time-critical activities together with background unscheduled access for less critical activities.

Deterministic and synchronized transfers can be provided at cyclic intervals up to 1 ms and device separations of 25 km. This performance is adjustable dynamically and on-line by reconfiguring the parameters of the local link whilst normal operation continues. By similar means, DL connections and new devices may be added or removed during normal operation.

This protocol provides means to maintain clock synchronization across an extended link with a precision better than 10 µs.

This protocol optimizes each access opportunity by concatenating multiple DLSDUs and associated DLPCI into a single DLPDU, thereby improving data transfer efficiency for datalink entities that actively source multiple streams of data.

The maximum system size is an unlimited number of links of 99 nodes, each with 255 DLSAPaddresses. Each link has a maximum of 2²⁴ related peer and publisher DLCEPs.

Cross References:
ISO/IEC 7498-3
IEC 61784-3-2
ISO 11898:1993
IEC 62439-3:2012
IEC 61158-3-2:2014/AMD1:2019
BS EN 61158-5-2:2019
IEC 62026-3:2014
IEC 61158-6-2:2014
IEC 61588:2009
IEC 61158-3-2:2014
IEC 61158-5-2:2019
IETF RFC 2131
IETF RFC 5227:2008
IEEE Std 802.1D-2004
IETF RFC 2132
IETF RFC 951
ISO/IEC 3309
ISO/IEC/IEEE 8802-3
IEEE Std 802.1Q-2005
IETF RFC 5227
ISO/IEC 7498-1
IETF RFC 1643
IETF RFC 3635
IETF RFC 1213
IETF RFC 2863
IEC 61158-6-2:2019
IEC 61131-3
IETF RFC 1542
IETF RFC 4541
IEEE Std 802.3-2015
IEC 61784-2:2019
IEC 61158-1:2019
IEC 61158-2:2014
IEC 61784-1:2019
IETF RFC 791
ANSI X3J16
ANSI X3.66
ISO/IEC 9314-2
ISO/IEC 8802 (all parts)
IETF RFC 4702
IETF RFC 793
ANSI X3.159
IETF RFC 1350
NAMUR NE 44
ISO/IEC 10731


Replaces BS EN 61158-4-2:2014 which remains current

All current amendments available at time of purchase are included with the purchase of this document.