Best Quad otdr Comway MAX-600-M4 OTDR Review: The Ultimate SM+MM 4-Wavelength OTDR for Fiber Professionals
The Comway MAX-600-M4 is a professional-grade, quad-wavelength Optical Time Domain Reflectometer (OTDR) that supports both singlemode (SM) and multimode (MM) fiber testing in a single handheld device. With four wavelengths — 850 nm, 1300 nm, 1310 nm, and 1550 nm — it eliminates the need to carry multiple instruments on-site, making it one of the most versatile OTDRs available for field engineers and fiber optic contractors.
Whether you are commissioning a new FTTH network, validating data center cabling, or troubleshooting a long-haul backbone link, the MAX-600-M4 delivers the dynamic range, dead zone performance, and reporting capabilities required for professional-grade fiber testing.
Key Specifications at a Glance
| Parameter | Multimode (MM) | Singlemode (SM) |
|---|---|---|
| Wavelengths | 850 nm / 1300 nm | 1310 nm / 1550 nm |
| Dynamic Range | 28 / 26 dB | 38 / 36 dB |
| Event Dead Zone | ≤ 1.5 m | ≤ 1.5 m |
| Attenuation Dead Zone | ≤ 5 m | ≤ 5 m |
| Distance Range | Up to 80 km | Up to 250 km |
| Distance Accuracy | ± 1 m | ± 1 m |
| Sampling Resolution | 0.05 m | 0.05 m |
| Display | 7" Color Touchscreen | |
| Battery Life | 8+ hours | |
| Report Formats | PDF / SOR (Bellcore) | |
Note: Specifications above are representative values. Always refer to the official Comway datasheet for the latest figures.
Core Features and Why They Matter
1. SM + MM Quad-Wavelength in One Unit
The defining feature of the MAX-600-M4 is its ability to test all four major fiber wavelengths without swapping modules or carrying separate instruments. For contractors working on mixed-fiber projects — such as a campus network with multimode backbone and singlemode feeder cables — this translates directly into faster job completion and lower equipment costs.
2. High Dynamic Range for Long-Distance Testing
With a singlemode dynamic range of 38 dB at 1310 nm, the MAX-600-M4 can characterize fiber spans well beyond 100 km. This makes it suitable not only for FTTH last-mile testing but also for regional backbone verification and long-haul maintenance work.
3. Ultra-Short Dead Zones
An event dead zone of ≤ 1.5 m and an attenuation dead zone of ≤ 5 m allow the MAX-600-M4 to resolve closely spaced connectors and splices — a critical requirement in high-density data center environments where patch panels may be separated by only a few meters.
4. Auto OTDR Mode
The built-in Auto OTDR function automatically selects the optimal test range, pulse width, and averaging time based on the connected fiber. This reduces operator error and speeds up testing for field crews who may not be OTDR specialists.
5. Bellcore SOR Report Output
The MAX-600-M4 generates test reports in both PDF and SOR (Bellcore SR-4731) formats. SOR compatibility ensures that test data can be imported into third-party analysis software and submitted to network operators as part of formal acceptance documentation.
Typical Applications
- FTTH / FTTB Acceptance Testing: Verify splice loss, connector reflectance, and end-to-end attenuation on every subscriber drop before handover.
- Data Center Cabling Validation: Resolve near-end events on short multimode patch cords with sub-2-meter dead zone performance.
- Backbone Network Maintenance: Locate faults and measure loss on long-haul singlemode spans up to 250 km.
- Mixed-Fiber Campus Networks: Switch between MM and SM wavelengths on a single device without reconfiguration.
- Emergency Fault Localization: Rapidly pinpoint cable breaks or high-loss events to minimize network downtime.
How the MAX-600-M4 Compares to Single-Wavelength OTDRs
| Feature | MAX-600-M4 (Quad) | Typical Single-Wavelength OTDR |
|---|---|---|
| Wavelength Coverage | 850 / 1300 / 1310 / 1550 nm | 1310 nm or 1550 nm only |
| Fiber Type Support | MM + SM | SM only (typically) |
| Instruments Required | 1 | 2–3 |
| Field Efficiency | High | Moderate |
| Report Formats | PDF + SOR | Varies |
| Best For | Mixed-fiber, multi-project teams | Dedicated SM or MM projects |
Who Should Buy the Comway MAX-600-M4?
The MAX-600-M4 is the right choice for:
- FTTH contractors who need to test both multimode jumpers and singlemode feeder cables on the same job site.
- Data center operations teams requiring short dead zone performance for high-density patch panel environments.
- Telecom engineers who must submit Bellcore SOR-format acceptance reports to network operators.
- Equipment rental companies looking for a single OTDR that satisfies the widest range of customer requirements.
- Network integrators managing mixed-technology infrastructure across enterprise and carrier environments.
If your work is exclusively on singlemode fiber and you do not require multimode capability, consider the Comway MAX-600-M1 (32/30 dB) or the Comway MAX-600-M2 (40/38 dB) for higher dynamic range at a lower price point. For PON and live-fiber testing with a 1625 nm wavelength, the Comway MAX-600-M3 is the recommended option.
Frequently Asked Questions
What fiber types does the Comway MAX-600-M4 support?
The MAX-600-M4 supports both multimode (MM) fiber at 850 nm and 1300 nm, and singlemode (SM) fiber at 1310 nm and 1550 nm. It is compatible with OM1, OM2, OM3, OM4 multimode fiber and OS1, OS2 singlemode fiber.
What is the maximum test distance of the MAX-600-M4?
The MAX-600-M4 can test singlemode fiber spans up to 250 km and multimode fiber spans up to 80 km, depending on the selected wavelength and fiber attenuation characteristics.
Does the MAX-600-M4 support Bellcore SOR report format?
Yes. The MAX-600-M4 exports test results in both PDF and SOR (Bellcore SR-4731) formats, making it compatible with industry-standard OTDR analysis software and suitable for formal network acceptance documentation.
What is the event dead zone of the Comway MAX-600-M4?
The event dead zone is ≤ 1.5 m and the attenuation dead zone is ≤ 5 m. This short dead zone performance allows the instrument to resolve closely spaced connectors and splices, which is especially important in data center and high-density cabling environments.
How does the MAX-600-M4 differ from the MAX-600-M1, M2, and M3?
The MAX-600-M4 is the only model in the MAX-600 series that supports both multimode and singlemode fiber with four wavelengths. The M1 and M2 are singlemode-only OTDRs with different dynamic range levels (32/30 dB and 40/38 dB respectively). The M3 adds a live-fiber 1625 nm wavelength for PON testing but does not include multimode capability.
Is the Comway MAX-600-M4 suitable for FTTH network testing?
Yes. The MAX-600-M4 is well-suited for FTTH acceptance testing, including splice loss verification, connector reflectance measurement, and end-to-end attenuation testing on both feeder and distribution fiber segments.
Conclusion
The Comway MAX-600-M4 stands out as one of the most capable all-in-one OTDRs in its class. Its quad-wavelength SM+MM design, combined with a short dead zone, high dynamic range, and Bellcore SOR reporting, makes it a practical investment for any fiber optic professional who works across multiple fiber types and project environments.
For teams that need to consolidate their test equipment without sacrificing measurement performance, the MAX-600-M4 delivers a compelling combination of versatility and precision.
→ View the Comway MAX-600-M4 product page and request a quote