# Fibre-optic link symbol

Canonical URL: https://eloragrid.ai/symbols/iec-fibre-optic-link-symbol
Publisher: Elora Grid
Updated: 2026-10-28
Lookup label: FO
Drawing use: Schematic, GA
Reference families: IEC

## Symbol convention

Convention: IEC
Form: Optical fibre link
IEC 60617 installation-plan style (architectural and topographical installation symbols); independently drawn, not certified IEC geometry or a database identifier.

Symbol for an optical fibre link between devices, a line with a fibre mark, often with media converters at each end.

## In plain English

### What does Fibre-optic link mean?

Fibre-optic links are drawn as a line carrying a fibre indication, such as a small loop, a wavy section or the tag FO, between the devices they connect. Network diagrams also show the fibre count and type, such as 12-core single-mode.

### A simple example

Electrical drawings use fibre links for substation communications, between buildings and through areas with electrical noise or earth potential rise, because fibre gives electrical separation without a direct conducting path. The symbol is often terminated in a media converter or switch fibre port. The symbol does not specify connectors, loss budget or route. The fibre schedule and test results cover these.

### What the drawings help you do

Read core count and fibre type. Find the termination at each end. A copper data cable has no isolation benefit; the fibre link isolates the two ends electrically.

### This particular reference

Symbol for an optical fibre link between devices, a line with a fibre mark, often with media converters at each end. A copper data cable has no isolation benefit; the fibre link isolates the two ends electrically.

### Terms

- Terminal: An identified point where a conductor connects.
- Schematic: A drawing showing function and connections rather than physical appearance.

Concept diagram: Identify the device and form → Read the connections and state → Check the equipment reference
A guide to reading this reference. The original symbol illustration and its drawing notes appear below; these boxes are not a wiring diagram.

- [IEC graphical symbols for diagrams](https://tc3.iec.ch/tc-activity/graphical-symbols-for-diagrams/)
- [Industrial Ethernet to fibre media converters](https://www.westermo.com/products/converters/ethernet-media-converters)
- [Autodesk IEC-60617 preview: Propagation and signal-flow qualifiers](https://help.autodesk.com/cloudhelp/2021/ENU/AutoCAD-Electrical/files/GUID-1C0C7AE2-F703-4283-BCB1-3E0B30882715.htm)


## What it represents

Fibre-optic links are drawn as a line carrying a fibre indication, such as a small loop, a wavy section or the tag FO, between the devices they connect. Network diagrams also show the fibre count and type, such as 12-core single-mode.
Electrical drawings use fibre links for substation communications, between buildings and through areas with electrical noise or earth potential rise, because fibre gives galvanic isolation. The symbol is often terminated in a media converter or switch fibre port. The symbol does not specify connectors, loss budget or route. The fibre schedule and test results cover these.

## How to read it

- Read core count and fibre type.
- Find the termination at each end.

## Information to show or reference

- State fibre type and cores.
- Show terminations.
- Reference loss test results.

## Important distinction

A copper data cable has no isolation benefit; the fibre link isolates the two ends electrically.

## Facts

- Benefit: Galvanic isolation and noise immunity
- Key data: Fibre type and core count
- Exact standard graphic: Not reproduced here; confirm the form against IEC 60617 and the project legend

## Public references

- [IEC graphical symbols for diagrams](https://tc3.iec.ch/tc-activity/graphical-symbols-for-diagrams/) — IEC. IEC graphical symbol context for installation and communication plans; independently drawn here.
- [Industrial Ethernet to fibre media converters](https://www.westermo.com/products/converters/ethernet-media-converters) — Westermo. Public product family page describing copper Ethernet to fibre conversion.
- [Autodesk IEC-60617 preview: Propagation and signal-flow qualifiers](https://help.autodesk.com/cloudhelp/2021/ENU/AutoCAD-Electrical/files/GUID-1C0C7AE2-F703-4283-BCB1-3E0B30882715.htm) — Autodesk. Public IEC-oriented propagation and signal-flow qualifiers used on communication symbols.

## 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.