BotBlox SPEBlox-Long (10BASE-T1L) - 10Mbps, 1km range, single pair ethernet

SPEBlox Long is a communication device that provides 10Mbps at extremely long cable runs up to 1,000m (1km) over simple twisted pair copper cable.

This technology uses the 10BASE-T1L specification, and this board aims to provide a cheaper and simpler way of achieving a 10Mbps bandwidth communication over very long cable runs.



SPEBlox Long is 31mm x 31mm and provides a standard 10BASE-T ethernet connection on Picoblade header (much like our other products). The 10BASE-T1L (single pair ethernet) connection is placed onto a screw terminal for full flexibility of cable types. The board is powered by any voltage from 5-60V and draws around 500mW (0.5W) of power at full operation.

SPEBlox Long is perfect for the following applications:

• Tethers for under water robots
• Factory communication infrastructure
• Any application requiring a simple, low cost, robust connection between physically disparate devices 
  

No customer configuration is required on SPEBlox Long, however a microcontroller is embedded onboard for communication management options.

This board is shipped with the following cables:

• 1 x PicoBlade to RJ-45 300mm (SKU: BB-PBRJ1-4-0.3)
• 1 x PicoBlade to Tinned Leads 300mm (SKU: BB-PBTL1-4-0.3)

The single pair ethernet connection can be made via the screw terminal using any single pair cable. We recommend using 28AWG, or any CAT6+ type conductor pair.

INCLUDED CABLES

We include everything you need to make this board work out of the box. Each board ships with:

1 x Molex PicoBlade to RJ-45, 4 way, 0.3 meter (Data cables)
SKU: BB-PBRJ1-4-0.3

1 x Molex PicoBlade to Tinned Leads, 4 way, 0.3 meter (Power cables)
SKU: BB-PBTL1-4-0.3

What cable should I use?

10BASE-T1L is a little more sensitive that 10BASE-T or VDSL when it comes to cabling type. We've found it important to use good quality CAT5-E (or higher) cabling with a known differential impedance of 100 Ohms. You do not need to use shielded CAT5-E, though if your environment is high EMI, a shielded cable is better.

Here is a link to the type of cable we use in our 1km test, and here is the characterisation data of that cable.

Power over Data Line (PoDL) is now possible
Many long reach 10BASE-T1L applications can be greatly simplified if power can be transmitted on the same pair as the data. To achieve this requires power circuitry to be added to the SPE terminals, to allow voltage to be injected at one end, and extracted at the other. 

On SPEBlox Long, the footprints for this circuitry is present, but the components are not populated by default. You can order a variant of SPEBlox Long that has these components populated (the part number is BB-SPL-A-2-PODL). Please get in touch for a quote on this part.

When using two BB-SPL-A-2-PODL together, only one needs to be powered, and the other is powered from the PODL on the twisted pair cable. BB-SPL-A-2-PODL has a reduced transmission length of 610 meters (as opposed to 1000 meters). The table below details the performance comparison between BB-SPL-A-2 and BB-SPL-A-2-PODL).

Read our blog post for test results on PoDL.