Fiber Optic Cable Locators & OTDR Modules
Field-ready and OEM fiber monitoring instruments — from the GY-FOCL turnkey cable locator that combines DAS vibration sensing with OTDR attenuation mapping, to compact GY-NK75 OTDR modules for integrating optical link monitoring into custom chassis and test systems.
- DAS + OTDR dual mode Two-step fault location on GY-FOCL
- Up to 80 km OTDR 40 km DAS vibration sensing range
- Mobile APP Real-time cable ID in the field
- OEM OTDR module GY-NK75 for embedded link monitoring
Monitoring Instruments by Application
Turnkey Fiber Optic Cable Locators
Portable instruments for telecom and utility O&M — OTDR first pinpoints optical attenuation anomalies along the line, then DAS confirms the exact fault or target cable when technicians tap the fiber on site. Ideal for manhole cable sorting, buried pipeline inspection, and data-center bundle identification.
OTDR Modules for OEM Integration
Compact OTDR-75 modules (GY-NK75) for embedding in optical fiber monitoring systems — single- or dual-wavelength variants with RS-232 control, low power draw, and dynamic range suited to link health checks in custom field instruments or rack-mounted monitors.
How to Choose the Right Monitoring Instrument
- Need a field tool for cable tracing and fault confirmation? GY-FOCL is a complete portable locator with DAS + OTDR dual positioning, mobile APP, and industrial enclosure — no separate DAS or OTDR hardware required.
- Building your own fiber monitoring chassis or test set? GY-NK75 OTDR module integrates via RS-232 into your host software — choose NK75S (1550 nm) or NK75D (1310/1550 nm dual-wavelength) depending on link type.
- Sorting bundled fibers in a trench or computer room? GY-FOCL DAS vibration mode identifies the tapped cable among many parallel fibers after OTDR narrows the search region — faster than OTDR-only testers.
- Deploying continuous perimeter or pipeline DVS/DAS monitoring? See our DAS modules & systems for distributed sensing hosts; GY-FOCL and GY-NK75 address point/link test and O&M rather than 24/7 zone monitoring.
- Need only attenuation/event location without vibration confirmation? GY-NK75 OTDR covers standard reflectometry tasks; pair with your own UI or use GY-FOCL when dual-mode verification is required on site.
For distributed vibration sensing system design, read our DVS technical guide or browse fiber sensing applications.
What Are Fiber Optic Monitoring Instruments?
Fiber optic monitoring instruments help operators locate faults, verify cable routes, and assess link health on installed optical networks. Unlike distributed sensing systems that monitor km-scale zones continuously, these tools focus on targeted measurement during installation, maintenance, and troubleshooting.
YB Photonics offers two complementary approaches: the GY-FOCL cable locator merges high-precision OTDR attenuation mapping with DAS vibration feedback and a mobile APP for two-step field positioning; the GY-NK75 OTDR module provides a compact reflectometry engine for OEM builders integrating link monitoring into custom hardware. Both complement our DAS/DVS sensing modules used in security, pipeline, and utility monitoring projects.
Key Specifications to Compare
| Parameter | Why it matters | Typical range in this category |
|---|---|---|
| Detection technology | OTDR-only vs DAS + OTDR collaborative | GY-FOCL dual mode; GY-NK75 OTDR only |
| OTDR reach | Maximum link length for attenuation events | Up to ~80 km (GY-FOCL); module-dependent (GY-NK75) |
| DAS vibration range | Distance for tap-to-confirm cable ID | Up to ~40 km (GY-FOCL) |
| Form factor | Portable field unit vs embeddable module | GY-FOCL handheld; GY-NK75 OEM module (+3–5 V) |
| Interface | How operators or host software control the device | Mobile APP (GY-FOCL); RS-232 serial (GY-NK75) |
| Fiber type | Compatible cabling | Single-mode (GY-FOCL); SM per module spec (GY-NK75) |
Frequently Asked Questions
- What is the difference between GY-FOCL and GY-NK75?
- GY-FOCL is a complete field instrument combining OTDR and DAS with a mobile APP for cable locating and fault confirmation. GY-NK75 is an OTDR module only — designed to embed in your monitoring system via RS-232, without on-board DAS or a handheld enclosure.
- How does DAS + OTDR dual positioning work on GY-FOCL?
- OTDR first identifies the optical attenuation anomaly along the fiber. Technicians then tap the suspected cable on site; the built-in DAS captures vibration along the line and cross-checks with OTDR data to confirm the exact fault point or distinguish one cable among bundled fibers.
- Can GY-NK75 replace a full OTDR test set?
- GY-NK75 provides reflectometry measurement core — dynamic range, pulse width, and range settings via serial control. You supply host software, display, and enclosure. It suits embedded link monitoring rather than a standalone handheld OTDR with full field UI.
- Are these the same as DVS/DAS perimeter monitoring systems?
- No. DVS/DAS systems (see our DAS modules) provide continuous distributed vibration monitoring along sensing fiber. GY-FOCL and GY-NK75 are O&M and integration tools for link test, cable sorting, and embedded OTDR — different deployment model and software.