RJ45 Patch Cord Identification: LED Patch Cord or PATCHSEE - Which Technology for Your LAN Network?

Identifying an RJ45 cable in a patch panel without unplugging it: 
the right technology makes all the difference

In a LAN network cabinet concentrating more than 200 RJ45 patch cords in under one square metre, tracing the other end of a cable should not be a guessing game. And yet, for too many network admins and IT installers, it still is. Reliable LAN cable identification saves time on every intervention, reduces human errors, and keeps the patch panel manageable over the long term.

For roughly twenty years, two technology families have shared the market for luminous-identification RJ45 patch cords: on one side, the passive optical solution PATCHSEE (plastic optical fibres, patented by 3P Design), on the other electrically-powered LED RJ45 patch cords. Both deliver immediate cable identification, but the technical differences are far from trivial. This guide details, for a professional audience, what really separates these two approaches: ISO/TIA standards compliance, high-density compatibility, color clips, injection tool, marking, PoE compatibility, and use cases in datacenters and enterprise LAN networks.

Two luminous-identification RJ45 patch cord technologies: how do they work?

PATCHSEE: two plastic optical fibres, 100% passive

The PATCHSEE system, invented and patented by French company 3P Design, uses two Plastic Optical Fibres (POF) bent at 180 degrees inside the RJ45 connector and its boot. The technician places the light injection tool (the PatchLIGHT) at one end of the cable, against the rear of the boot; light travels through the optical fibre to the other end of the patch cord, where it exits visibly, without unplugging the patch cord, without any electrical current, and without interference on the Ethernet twisted pairs.

This unique optical technology is built into the PATCHSEE, ThinPATCH, and DirectPATCH RJ45 patch cords, available in lengths from 15 cm to 30 m.

LED RJ45 patch cords: luminous identification via electrical power

LED RJ45 patch cords of the DualBoot® type (notably saCon) or with integrated button cells (the EVO range, for example) use a different principle: two LEDs, one at each end, housed in the boots of the RJ45 connectors. Power is supplied either via an external tool with LR41 button batteries that connect to electrical pins on the rear of the RJ45 connectors, or via a button cell integrated directly in the boot.

To carry current between both ends, the manufacturer adds an electrical wire inside the RJ45 cable, between the twisted pairs. On a shielded cable (U/FTP, F/UTP, S/FTP), the ground drain is used as the return conductor. This is the technical point that raises a normative issue, detailed below.

The real issue: compliance with ISO/IEC and TIA/EIA standards

This is the most technically critical argument, and it is too rarely raised by IT hardware distributors. The structured cabling standards ISO/IEC 11801 and TIA/EIA-568 define precisely what an Ethernet RJ45 cable contains: four twisted pairs, and optionally a shield and drain for screened cables. No normative provision authorises the circulation of an additional DC current in an added conductor, nor the use of the drain as an electrical conductor for LED power supply.

Adding an electrical wire to power LEDs, and using the ground drain to close the electrical circuit, therefore falls outside the framework defined by these standards. PATCHSEE, by contrast, is a 100% passive technology: the injected light travels only through dedicated plastic optical fibres (POF), completely independent from the Ethernet pairs and the drain. No interference is possible on network frame signals, and there is no risk to the ground continuity of a shielded cable.

Key takeaway: a standards-compliant luminous-identification RJ45 patch cord is a passive cord. The LED RJ45 patch cord, by design, passes current through the cable, which neither ISO nor TIA validates.

High-density environments: PATCHSEE fits, DualBoot® does not

In a modern datacenter or on a high-density switch (48 ports or more in 1U), every millimetre counts. PATCHSEE connectors are designed with boots aligned to the edges of the RJ45 plug: no lateral overhang, no overhang on the contact side. As a result, PATCHSEE and ThinPATCH patch cords insert without constraint into high-density panels and switches, including side-by-side ports.

LED RJ45 patch cords must house the LED and its power contacts inside the boot, which forces a wider boot than the RJ45 plug itself. The direct consequence: LED cords of the DualBoot® type cannot be used in high-density environments. Two adjacent cords block each other, and the oversized boot forces against the neighbouring port.

For any datacenter project, dense network cabinet, or 48-port switch, the choice of a high-density compatible luminous-identification RJ45 patch cord is therefore decisive.

Color clips: first-level identification in the patch panel

In an enterprise LAN network, first-level color coding remains indispensable to distinguish, for example, the data network, telephony, CCTV, access control, fire alarm, or simply to differentiate geographic zones. Two approaches exist: color-coded patch cords, or removable color clips that mount on the connector boots.

PATCHSEE offers 16 colors of removable PatchCLIP, with a dual benefit: they remain visible even in a loaded rack, and they protect the RJ45 plug locking tab from breakage during extraction. Two clips per cord are enough to assign the RJ45 patch cord to an application or a geographic zone.

On the LED RJ45 patch cord side, the bulk of the diode inside the boot forces manufacturers to use tiny clips (approximately 7x2x1.5 mm). In practice they are difficult to handle for an installer, and their visibility is very low once the rack is fully loaded. Some models (the EVO range with integrated button cell) simply do not offer removable color clips at all.

Bend radius strain reliever: a network performance issue

ISO/IEC 11801 and TIA/EIA-568 recommend securing RJ45 cables with hook-and-loop straps, never with plastic cable ties that pinch the cable. A pinch, a tight bend, or excessive curvature degrades the cable's electrical characteristics: Return Loss (RL) and Near-End Crosstalk (NEXT) collapse, and a certified CAT 6A cable drops in real performance to CAT 6, or even CAT 5e levels. The direct consequence on throughput: unstable 10 Gb/s, or a drop back to 1 Gb/s.

PATCHSEE CAT 6 and CAT 6A RJ45 patch cords, and the ThinPATCH range, integrate a bend radius strain reliever at the boot exit. This protects the most sensitive zone of the patch cord, which is precisely the zone most mechanically stressed in an active patch panel.

Light injection tool: PatchLIGHT versus button cell power supplies

On the PATCHSEE side, the injection tool is called the PatchLIGHT. It is a 5-LED, 30,000-lux light source, available in three colors (red, green, white), with two modes (steady or flashing). It runs on rechargeable batteries; when flat, it plugs directly into a 220 V mains socket at the bottom of the rack and continues to function. It positions one-handed against the rear of the boot, and its cord with clip allows it to hang in the rack during an intervention. Three colors combined with two modes means multiple simultaneous identification operations are possible in a single patching session.

Some technicians even use the torch function of their smartphone to inject light into the plastic optical fibre, which demonstrates how practical the technology is.

LED RJ45 patch cords, by contrast, require LR41 button-cell power, batteries rarely found in a standard stock. Targeting the small electrical contacts on the rear face to connect the power source is more fiddly, especially when the cable is curved. And when the batteries run out, they need to be on hand. No mains alternative, no direct rechargeability.

Marking, lengths, and stock logistics

A final technical point, often underestimated: boot marking. All PATCHSEE, ThinPATCH, and DirectPATCH RJ45 patch cords carry the product reference (useful for reorder) and the exact cable length on the boot. This is also a valuable troubleshooting indicator: a cord marked "1.5 m" almost certainly stays in the same cabinet; one marked "10.0 m" is most likely going to an adjacent rack.

For available lengths, 3P Design offers a 30 cm increment from 15 cm to 3.0 m, then 4.0 m and 5.0 m, and longer lengths up to 30 m. The goal is simple: keep patch panels well-ventilated, with no excess cable cluttering cable managers and impairing airflow.

ThinPATCH CAT 6A slim: space saving and PoE++ (4PPOE)

The ThinPATCH range pushes the logic further with a slim CAT 6A cable:

• U/UTP: 3.8 mm diameter
• U/FTP: 4.5 mm diameter
• PoE++ (4PPOE) compatible, meaning full 4-pair PoE up to the highest power classes

The measurable benefits for a network admin or low-voltage installer:

• Significant space saving in patch cabinets, cable managers, and cable trays
• Greater ease of use during patching, maintenance, and troubleshooting
• Better rack airflow, reducing thermal stress on switches and lowering failure risk
• More flexible cable: easier patching and access, particularly on high-density panels

ThinPATCH inherits the full PATCHSEE luminous identification technology and all PatchCLIP color options.

Comparison table: RJ45 PATCHSEE vs LED RJ45 patch cord

Which solution by country and LAN network type?

Not all European markets use the same structured cabling. This point is critical for choosing the right product:

• Germany (DE) and Austria (AT): near-exclusive use of shielded LAN cable (U/FTP, F/UTP, S/FTP). Luminous-identification RJ45 patch cords must be available in shielded versions, which is the case for PATCHSEE. LED DualBoot® cords that require the drain can exist in shielded versions, but remain subject to the normative reservations above.
• France (FR) and Switzerland (CH): approximately 30% shielded cabling, 70% unshielded. PATCHSEE and ThinPATCH cover both. LED RJ45 patch cords of the DualBoot® type do not exist in U/UTP, which excludes the majority of installations.
• United Kingdom (UK), Ireland (IE), Spain (ES), Italy (IT), Benelux (BE, NL): predominantly U/UTP. Only passive solutions such as PATCHSEE and ThinPATCH allow reliable luminous identification on unshielded cable, since there is neither a drain nor a need for electrical power.
• International datacenters: regardless of the country, the high-density constraint alone decides. PATCHSEE and ThinPATCH pass. LED RJ45 patch cords with oversized boots do not.
• USA and Asia: predominantly U/UTP. LED cords requiring a drain are inapplicable. PATCHSEE and ThinPATCH are the only universal LAN cable identification solution.

Positioning against market alternatives

Several names come up when discussing cable management and luminous patch cords: saCon (DualBoot® LED cords, strong presence in DE/AT), EVO (LED cords with integrated button cell, no removable color clip), PatchBox (retractable patch cord solution, a different problem focused on space saving), Ubiquiti (UniFi ecosystem: router, switch, Wi-Fi access point, telephony, with accessory patch cords). None of these alternatives simultaneously combines:

• passive luminous identification compliant with standards,
• high-density compatibility,
• 16 color clips protecting the RJ45 plug,
• slim CAT 6A PoE++ range,
• reference and length marking.

This is precisely the scope covered by the 3P Design product family (PATCHSEE, ThinPATCH, PatchCLIP, PatchLIGHT).

To understand the complementarity between the PATCHSEE system and Ubiquiti, read our article "PATCHSEE vs Ubiquiti comparison".

Summary: which luminous-identification RJ45 patch cord to choose for your LAN network?

If your specification includes, even partially, any of the following points, the passive PATCHSEE / ThinPATCH solution is objectively the most appropriate:

• Full compliance with ISO/IEC 11801 and TIA/EIA-568 without exception,
• U/UTP LAN network (any country outside DE/AT majority usage),
• High-density patch panel, 48-port switch, datacenter,
• Color coding that is practical by hand and visible at distance in a loaded rack,
• PoE / PoE+ / PoE++ 4PPOE on slim cable,
• A light injection tool that is always available (rechargeable + mains).

LED RJ45 patch cords retain one simple advantage, the raw luminous power of a diode, but in a standard network room (technical rooms with no direct sunlight), the light from a PATCHSEE optical fibre is perfectly sufficient for LAN cable identification in a few seconds.

Testing before equipping an entire site is the best way to decide. Request your free ThinPATCH demonstration kit to evaluate the luminous identification, high-density compatibility, CAT 6A slim cable thickness, and patching comfort under real conditions.