How to identify optical cable markings

Optical cables feature printed legends and color codes on their jackets that indicate fiber type, core size, fire rating, manufacturer, and installation specifications. Printed Legends on Cable JacketsFiber optic cables often have text printed along the outer jacket that provides essential information for identification and installation. Common details include: Fiber type and mode: Single-mode (SM, 9/125 µm) or multimode (MM, e.g., 50/125 or 62.

5/125 µm) indicating core and cladding diameters and performance grade (OS1, OS2, OM1–OM4). Cable construction and application: Terms like “Micro Distribution,” “Direct Burial,” or “Tactical” describe the intended use and physical design. Fire and safety ratings: Abbreviations such as OFNR, LSZH, or FT4 indicate compliance with fire safety standards and suitability for indoor or outdoor installation.

Manufacturer and product info: Brand name, model number, serial number, and date of manufacture help track production and warranty. Physical specifications: Minimum bend radius (MBD), cable diameter, weight per unit length, and maximum pulling tension are often printed to guide safe installation. Distance markings: Some cables include length indicators along the jacket to track usage during deployment.

Color Coding

Fiber optic cables also use standardized color codes for quick visual identification: Outer jacket colors: Indicate fiber type; for example, yellow for single-mode (OS1/OS2), orange for OM1 multimode, aqua for OM3/OM4 multimode, and sometimes violet for OM4 in high-density environments. Individual fiber strands: Follow the TIA/EIA-598C 12-color sequence (blue, orange, green, brown, slate, white, red, black, yellow, violet, rose, aqua) to identify fibers within a multi-fiber cable. For cables with more than 12 fibers, the sequence repeats with stripes or tube-based coding.

Connector colors: Indicate polish type; blue for UPC (flat), green for APC (angled) to prevent mismatched connections.

Summary

By reading both the printed legends and color codes, technicians can determine the fiber type, core size, fire rating, manufacturer, installation limits, and individual fiber identification. This ensures proper handling, safe installation, and compatibility with network equipment, reducing errors and improving operational safety.