M8 Cable

What It Is

The Growlink M8 Extension Cable (GLM8-5M) is a 5-meter sensor extension cord built specifically for the Growlink LINKS platform. It terminates on both ends with threaded 4-pin M8 connectors — the same standard used across the LINKS ecosystem — so it bridges any gap between a sensor and a canopyLINK port without adapters or custom wiring.

The cable ships as a single extension. For installations that also need to branch or split a sensor run, Growlink offers a separate M8 Extension Cable Kit that bundles this 5m cable with a T-connector and an end cap for terminating unused ports. The GLM8-5M alone is the right pick when you simply need more reach on a single sensor run.

Who Needs It

Commercial indoor and greenhouse operators running Growlink LINKS hardware will encounter this cable whenever sensor placement and hub position don't line up cleanly. The canopyLINK hub carries eight M8 ports and is typically mounted centrally above the canopy. TerraLINK substrate sensors ship with a 2m M8 cable from the probe — workable in a compact room, but rarely enough in a multi-bench or multi-zone facility.

Any operator using rolling benches, wide bay greenhouses, or rooms where the sensor needs to reach from a bench edge or corner back to a centrally hung canopyLINK will need extension cable. Rather than repositioning the hub or leaving a sensor port empty, the GLM8-5M lets you place each sensor exactly where it reads best — at the root zone — and route cable cleanly back to the hub.

Key Features

The M8 connector is an industry-standard threaded locking format. On the Growlink LINKS system, M8 connections are 4-pin threaded male-end connections. The threaded collar locks the mating halves together, which matters in a grow room environment where water, vibration from fans, and cable movement can work push-fit connectors loose over time.

The cable is built for cultivation conditions — high humidity, occasional spray, temperature swings. The construction is designed to hold up in greenhouse tunnels and indoor grow rooms where lesser cabling degrades signal integrity over a season. Because the LINKS platform uses SDI-12 communication over its M8 sensor lines, maintaining clean signal with no dropouts is critical to accurate VWC, EC, CO2, temperature, and RH readings feeding into Growlink OS.

How It Fits a Growlink LINKS Build

In a typical LINKS installation, the canopyLINK hub is mounted centrally and connects up to eight sensors across the room. Each sensor port is an M8 connection. TerraLINK substrate sensors and ClimaLINK climate sensors both terminate in M8 connectors, and the canopyLINK automatically addresses each sensor when it's connected — no manual configuration required. When a sensor's native cable isn't long enough, the GLM8-5M daisy-chains inline between the sensor and the hub port.

The Growlink knowledgebase recommends locating the canopyLINK centrally and factoring in rolling bench positions and sensor cable extensions when planning the installation. Having the GLM8-5M on hand before commissioning a room avoids the common issue of a sensor port going unused because a run is 3–4 feet short. For operators phasing in additional sensors over time, keeping spare extension cable in the facility prevents data gaps mid-cycle.