10BASE-T1L Patch Cord for Single Pair Ethernet, T1 Industrial or M8

Overview

A 10BASE-T1L patch cord carries Ethernet over a single twisted pair, which is
the change that makes the economics work at the edge of a building or a plant. Four-pair cable is
expensive to buy, heavy to pull and awkward to terminate in a small sensor, and for a valve
positioner or a room sensor it is far more cable than the data requires. The physical layer and
the management parameters for this application are defined in IEEE 802.3cg, running 10 Mbit/s
over distances quoted up to 1000 m on one pair, which puts devices that previously needed a
gateway onto an IP network directly.

Key Specifications

What single pair actually changes on a job

The obvious saving is copper. The real saving is everything attached to it: a smaller cable
means a smaller gland, a smaller conduit, a smaller terminal block and a connector that fits on a
device the size of a matchbox. On a retrofit into existing conduit, that difference is often the
deciding factor rather than the cable price.

The honest counterweight is that single pair Ethernet is new to most installation teams. The
pair balance matters more, the untwisted length at the termination matters more, and the topology
rules are different. Budget time for the first run, not just the cable.

802.3cg, and the two flavors people confuse

The IEEE
802.3 working group published 802.3cg with two physical layers in it, and confusing them puts the wrong
cable on site. 10BASE-T1L is the long-reach point-to-point variant, quoted up to 1000 m.
10BASE-T1S is the short-reach variant built for multidrop, where several nodes share a mixing
segment. They are not interchangeable.

Power on the same pair

Power over Data Lines, specified in IEEE 802.3bu, puts DC on the same pair that carries the
data. That is what removes the separate power drop to a sensor: one cord, one connector, one
gland. Competitor data quotes 60 V DC and 4 A class for this family. Those numbers are not
interchangeable with PoE figures, and the delivered power depends heavily on the loop resistance
of the run, so give us the length and the load before ordering and we will check the voltage drop
rather than quoting a class.

Connector options

Two mating faces are offered. The T1 Industrial interface to IEC 63171-6 is a small, keyed,
latching connector intended for single pair use; confirm the edition your project specifies. The
M8 option suits installations already built on M8 sensor wiring, or where an existing IP67 harness
has to be reused. Cords are offered at IP20 for panels and field cabinets and at IP67 for the
device end, and mixing the two on one assembly is normal. Where the device end has to be sealed
and screwed down, the 10BASE-T1L
screw lock cable is the variant to look at.

Where it is used

• Building automation trunks for HVAC actuators, valve drives and room sensors
• Lighting control segments where each luminaire becomes an addressable node
• Access control and metering points spread along a corridor or a riser
• Process instrumentation and IIoT sensor drops that were previously on a fieldbus

Installation reality

Reach and speed trade against each other, and the trunk is a bus, not a star: check the segment
rules for the multi-drop topology before you lay out spurs. Keep the pair twist right up to the
termination, since the balance that gives you the reach is destroyed by a couple of centimeters
of untwisted conductor at the connector. Screened constructions need the screen bonded at the
shell and referenced to earth at one point at least, and the run belongs out of the same conduit
as variable speed drive output.

What we are confirming

Reach, conductor size, current and voltage ratings, temperature range, mating cycles, oil
resistance and ingress ratings are quoted from public competitor data. Competitor literature also
quotes a 600 MHz bandwidth figure for this cable family; that describes the cable rather than a
10BASE-T1L link, and we do not publish it until the supplier states what was measured. Give us the
run length and load.

How to specify your build

1. Physical layer — 10BASE-T1L for long point-to-point, or 10BASE-T1S if the
   project is multidrop.
2. Connector — T1 Industrial to IEC 63171-6, or M8, and the edition you
   reference.
3. Ingress — IP20 for the panel end, IP67 for the device end, or both on one
   assembly.
4. Power — PoDL or data only, and the load at the device.
5. Run length and load, so the voltage drop can be calculated.
6. Quantity, and whether this is a prototype or a production order.

Typical applications for this 10BASE-T1L patch cord

• Field instrument trunks replacing 4-20 mA loops and legacy fieldbus drops
• HVAC and building automation segments, with our SPE
  bulkhead panel connector at the cabinet
• Sensor drops already built on M8, alongside our single
  pair Ethernet cable in M8 and M12 shells
• Valve islands and actuator manifolds, using the M12
  hybrid SPE cable where power and data share one cordset

Workmanship and testing

Workmanship on 10BASE-T1L Patch builds follows IPC/WHMA-A-620 Class 3, the line is run under ISO 9001, and the termination range is 32 to 12 AWG. No 10BASE-T1L assembly is boxed before 100% continuity and pinout are confirmed, and seal checking is quoted whenever an ingress rating is on the drawing.

RoHS and REACH declarations are provided per project together with the agreed test reports; the documentation scope is listed under certifications and compliance. If your drawing specifies a UL style, we build to that drawing and supply the UL reference with the shipment instead of substituting an equivalent. Production runs on the same lines described under the assembly lines behind this build, where cutting, termination, molding and 100 percent electrical verification sit under one roof. The wider context is covered under our industrial automation work. Any tooling we cut for this part stays yours, maintained in our own tool room under your part reference.

Custom builds and ordering

Quote 10BASE-T1L Patch builds from 1 to 50 pcs and they ship in 3 working days; at volume the minimum is 500 pcs with 14 working days after approval.

Related single pair and field assemblies

• 10BASE-T1L Screw Lock
  Cable with Sealed M8 or IEC 63171-6 Coupling
• Single Pair Ethernet
  Cable in M8 and M12 Shells for Sensor Runs
• SPE M12 Hybrid
  Single-Pair Ethernet + Power Cable
• SPE Bulkhead Panel
  Connector for 10BASE-T1L Field Devices
• M8 D-Coded Ethernet
  Cable, 4-Pin 100 Mbit Cordset

Full range: Ethernet
cable and patch cords.

Frequently Asked Questions