# PLC relay output

Canonical URL: https://eloragrid.ai/symbols/plc-relay-output
Publisher: Elora Grid
Updated: 2026-10-13
Lookup label: DO RELAY
Drawing use: Schematic
Reference families: Manufacturer

A PLC relay output switches a documented contact path through the module's relay interface.

## What it represents

A PLC relay output switches a documented contact path through the module's relay interface. The load supply and contact common may be separate from the PLC electronics supply.

## How to read it

- Trace the load source through the output contact and common terminal.
- The preview is an original explanation of this function. Match the actual drawing convention to its legend and the selected equipment documentation.

## Information to show or reference

- Identify output channel
- Show load supply/common
- Reference contact/load rating

## Important distinction

A relay output is a contact interface, not a transistor output with the same supply/common behaviour.

## Facts

- Drawing role: Controller interface
- Representation scope: Functional concept; not an official standard graphic or a product footprint
- Identifier status: The short label is a functional lookup label, not an assigned IEC or IEEE symbol number. Any separately listed Autodesk code is a verified vendor block name.

## Public references

- [Modicon TM3 digital I/O hardware guide](https://www.se.com/ca/en/download/document/EIO0000003125/) — Schneider Electric. Public documentation of this equipment function or named vendor variant; the illustration is independently authored and is not the source graphic.

## 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.