# Digital breaker-command output boundary

Canonical URL: https://eloragrid.ai/symbols/digital-breaker-command-output-boundary
Publisher: Elora Grid
Updated: 2026-11-03
Lookup label: DBOB
Drawing use: Schematic
Reference families: Manufacturer

Representation: Functional block
Installation focus: substations
Input: Accepted digital command
Output: Physical operating output

Shows the conversion from a received digital operating request to the assigned physical breaker output.

## In plain English

### What this block does

Shows the conversion from a received digital operating request to the assigned physical breaker output.

### A simple example

In a digital substation bay, a merging unit digitizes local measurements and a protective relay subscribes to the assigned data stream. The command return path and communication-health indications are drawn separately. For this reference, the drawing identifies “Accepted digital command” at the input and “Physical operating output” at the output. The output circuit still requires its normal supervision.

### What the drawings help you do

Start at the named input: Accepted digital command. Identify its source device or document and the state represented on the drawing. Follow the named output: Physical operating output. Cross-reference its destination and separate the command from confirmation that the equipment responded.

### Terms

- Input: Accepted digital command
- Output: Physical operating output
- Application reference: An explanation of a named drawing function or circuit relationship; the project documents define the equipment and its connections.

Concept diagram: Accepted digital command → DBOB → Physical operating output
A reading guide. The entry's original illustration and input/output facts describe this application.

- [Digital secondary systems: Sampled Values](https://selinc.com/solutions/digital-secondary-systems/sampled-values/)


## What it represents

Shows the conversion from a received digital operating request to the assigned physical breaker output. Digital substation interfaces carry measurements, status and control information between primary equipment and protective devices. Measurement streams, event messages and time synchronization are separate dependencies even when they share an Ethernet network.
In a digital substation bay, a merging unit digitizes local measurements and a protective relay subscribes to the assigned data stream. The command return path and communication-health indications are drawn separately. For this reference, the drawing identifies “Accepted digital command” at the input and “Physical operating output” at the output. The output circuit still requires its normal supervision.
Identify publisher, subscriber, data meaning and quality handling. Protocol labels alone do not establish protection performance, compatibility or network redundancy; these need the selected system configuration and validation. The functional block is an independent explanation of this named application. Equipment-specific ratings, terminal connections and operating conditions must be established in the project documentation.

## How to read it

- Start at the named input: Accepted digital command. Identify its source device or document and the state represented on the drawing.
- Follow the named output: Physical operating output. Cross-reference its destination and separate the command from confirmation that the equipment responded.
- The output circuit still requires its normal supervision.
- Identify publisher, subscriber, data meaning and quality handling. Protocol labels alone do not establish protection performance, compatibility or network redundancy; these need the selected system configuration and validation.

## Information to show or reference

- Label the source and connection reference for accepted digital command.
- Identify the destination and defined state of physical operating output.
- Record the equipment or control-document revision supporting this functional block.
- Check this application limit in the project design: The output circuit still requires its normal supervision.

## Important distinction

The output circuit still requires its normal supervision. This reference describes the named application; it does not establish a new IEC graphical symbol, an ANSI device-function number or an exact manufacturer connection diagram.

## Facts

- Representation: Functional block
- Installation focus: Substations
- Input / boundary: Accepted digital command
- Output / connection: Physical operating output
- Lookup label: DBOB is a library lookup label, not a standard device designation.

## Public references

- [Digital secondary systems: Sampled Values](https://selinc.com/solutions/digital-secondary-systems/sampled-values/) — SEL. Public technical context for digital substation process interfaces. Merging units, sampled measurements, GOOSE, process bus and network redundancy. The application text and educational graphic are independently authored; the publisher does not certify this representation.

## Graphic scope

Independent original educational concept illustration by Elora Grid. Not a certified standards graphic or manufacturer footprint. Unitless; not to scale. Original artwork licence: https://creativecommons.org/licenses/by/4.0/. Publisher material is linked only.