Toner and Probe for Cable Identification

Jul 12, 2025

Overview

This lecture introduces the use of a toner and probe (also known as a tone generator and probe) as tools for identifying and tracing network cables in a structured cabling system.

Purpose of a Toner and Probe

  • A toner and probe set is used to locate and identify specific cables in a bundle or at patch panels.
  • The toner sends an electrical signal or tone through a cable, which the probe can detect by sound.

How to Use a Toner and Probe

  • Connect the toner (tone generator) to one end of the cable you want to trace.
  • Use the probe on the cable bundle elsewhere to detect the tone emitting from the correct cable.
  • The probe produces an audible tone only when near the cable carrying the signal from the toner.

Common Applications

  • Useful for identifying unlabelled or misplaced cables in networking closets or patch panels.
  • Helps network technicians avoid disconnecting the wrong cable during troubleshooting or moves/adds/changes.

Safety and Limitations

  • Toner and probe should not be used on powered circuits, as it may damage the equipment.
  • The probe only detects the tone for the specific cable, not for electrical cables or other types of wires.

Key Terms & Definitions

  • Toner (Tone Generator) — A device that sends a distinct signal through a wire or cable to aid in identification.
  • Probe — A device that detects and amplifies the tone signal in a wire so it can be heard by the technician.
  • Patch Panel — A hardware assembly containing ports used to connect and manage network cables.

Action Items / Next Steps

  • Practice using a toner and probe on a test cable run to develop familiarity with the devices.
  • Review safety guidelines to prevent use on live or powered circuits.