Introduction to Device Level Ring
Anatoly Moldovansky, S. Balasubramanian, Brian Batke · 2009
There exists a class of applications in the industrial control market where a ring/linear network based on end nodes with integrated 2-port switches is more suitable than a conventional star network. Additionally, continuous system operation is required even when a single fault occurs in the end node, its network interface or cable system. Device Level Ring (DLR) is a fault tolerant network allowing realization of control systems with such requirements. This paper provides an introduction to DLR network 1 . It describes principle of operation of this network, its features, and performance. It also describes DLR protocol and presents recommendations for implementing the DLR interface.