Industrial Engineer · phase 5 of 16 · noun
Device Level Ring (DLR)
ODVA ring topology that provides rapid recovery from a single network break on supported EtherNet/IP devices.
The Explain card
- Plain English
- DLR is an EtherNet/IP ring topology with a supervisor that watches for a break. Devices with two ports are daisy chained into a loop, and if any cable fails the ring heals in a few milliseconds.
- Example
- Twelve I/O blocks along a conveyor are wired in a ring back to the controller. A forklift cuts one cable and the machine never notices.
- Why it matters
- A plain daisy chain loses every device past the break, and a ring keeps them all. The supervisor has to be configured, and a ring with no supervisor is a loop that floods the network the moment it closes.
- Hook
- A chain with both ends held.
Word knowledge
How the word is built, where it came from, and what it sits beside in memory.
In a sentence
During commissioning, the engineer enabled Device Level Ring supervisor mode on the EtherNet/IP switch and checked both network ports on every drive.
Why these words
- device Old French devis, plan or arrangement identifies the equipment endpoint layer
- level Old French livel, measuring instrument marks a layer within a network hierarchy
- ring Old English hring, circular band names the closed-loop physical arrangement
Where it came from
- Origin
- English technical compound formed from device, level, and ring, standardized by ODVA
- Entered the language
- 2008
- What changed
- Device came to mean a piece of equipment, level acquired the sense of a hierarchical layer, and ring was extended from circular objects to network layouts.
How it is spelled
- Pattern
- Each word retains its ordinary English spelling when joined as a three-word technical compound.
- Pattern
- The initialism DLR takes the first letter of each capitalized word.
Spelled like
- device-level network
- device-level architecture
- ring topology
Broken into chunks
-
device
- devices
- devicelike
-
level
- leveled
- leveling
-
ring
- ringed
- ringing
What it sits beside
Same subject
- EtherNet/IP
- ring supervisor
- ring node
- beacon frame
- network commissioning
Same shape
- Control Level
- Device Level
- Information Level
industrial network topologies
- ring topology
- linear topology
- star topology
DLR node roles
- ring supervisor
- ring node
Where it sits in the deck
Phase 5: PLC Industrial Communications
The protocols that let controllers, drives and operator panels talk, plus the addressing and description files that make them agree on what was said.
