10 mbit ethernet

Single pair 10BASE-T1S and 10BASE-T1L are alive and kicking. Used for industrial (replacement of sensor / actuator field busses) and automotive. Long distances, and/or multidrop.

"Two new variants of 10 megabit per second Ethernet over a single twisted pair, known as 10BASE-T1S and 10BASE-T1L, were standardized in IEEE Std 802.3cg-2019.[2] 10BASE-T1S has its origins in the automotive industry and may be useful in other short-distance applications where substantial electrical noise is present.[3] 10BASE-T1L is a long-distance Ethernet, supporting connections up to 1 km in length. Both of these standards are finding applications implementing the Internet of things."

Connectors, cables and most important PHY's are available.

Arie

That sounds good. I was mostly thinking about the usual 4-pair CAT6, so normal computers and hubs and things would work.

I have seen ethernet PHYs above 1GBit/s that do not support 10MBit/s anymore, but I don't have part numbers at hand.

OTOH, PC NICs drop their ethernet link to 10MBit/s in sleep mode to save power (for wake on lan) - not sure if these migrate to 100MBit/s or not.

cu Michael

Made me check for the dp8392... Still can be found (obviously old stock). Not many (but me...) have a coaxial Ethernet still running. And well, the 10Mbps hub has just one Nukeman behind itself... The hub is (I think) just physical, no "buffer and then retransmit". But works connected to a 10/100 hub to the "normal" network here. For how long hubs and PCs will allow that ... your guess is no worse than mine. Though some bridging will have to be feasible for a longer while, there are many 10/100 etc. switches around.

Am 02.12.22 um 17:14 schrieb John Larkin:

I've bought an interface box 10 MBit/s BNC <-> 1000 MBit/s (my normal LAN) for my 89441A FFT analyzer. Maybe €29,99 or so. Works wonderfully. Even if the RG58 cable is only

10 cm long, it needs both 50 Ohm terminations. Probably only a DC level thing. Source was Amazon.

Gerhard

The standard will never go away. The 10 Mbit speed has endured, mostly for factory automation. What is taking that niche over is fiber (versus CAT<something> twisted pair), largely for increased speed and essentially total resistance to EMI. There is a lot of activity involving use of plastic fiber in such as automobiles.

What are you trying to accomplish?

Joe Gwinn

We found coax ethernet to be flakey. Even short stubs or changes in cable length could break it.

There don't seem to be many Catx hubs or hub chips around either. Everything is a switch, which is usually good.

If I use a Raspberry Pi, there is an easy way to add ethernet, but it's apparently reliable at 10M only. That's enough for the data we want to move.

10BASE-T has only even needed half as many pairs and half as much CAT. (2 pairs on CAT3). Did you perhaps mean 10 gigbabit Ethernet above?

When I was playing with 10Base-2 over short cables (like 3m segment length) I found that I could put both terminators on one end of the cable and it would still work.

I think the collision detection is a "DC level thing"

Well on a single cable just one bad node can cause problems of course. But in general it works fine as long as all nodes behave.

A switch is good - better - in most typical circumstances. But you cannot use a switch to snoop on another host on the network like with a hub; then the latency with a hub is none, if that matters in some scenario.

I'm intrigued by you saying only "reliable" at 10M. Which RPi are we talking about and who says? And what is the unreliability?

Long ago, we had some computers wired, in theory for 100M. But it was actually doing 10M.

I found that the cable twisted pairs were 1-2, 3-4, 5-6, 7-8, instead of

1-2, 3-6, 4-5, 7-8. Electrically (DC) it is the same, but the transmission properties were different, the cards detected errors, and they dropped to 10M.

So we replaced those cables and the network went to 100 M.

Dunno what the cables were intended for, or if it was just an error when making the connectors (I did not have the tools to make them).

Modern chipsets and PHY for 10/100baseT are all you'll likely find; I'd guess that 100Mbit with error correction is just as good as 10 Mbit, but in any case all the available support chips are the same because it falls back. Two-pair 10baseT is very much obsolete, would be hard to find a dedicated chipset available today.

CAT6 has twice as many pairs as 10/100 uses. No CAT6 advantage, unless you want to run two links in a single cable.

The advantage is to use all the standard stuff, PCs and cables and switches and RJ45 connectors. Cat5 would certainly be OK at 10M.

Price is crazy low on either type of cable.

The Raspberry ought to be able to drive a faster NIC, so the Pi need not talk all that fast. May need a fast buffer memory somewhere.

What is the max link length?

Joe Gwinn

Pi Pico.

There is an add-on board to do Ethernet. We could use the same phy chip and software instead of buying the board.

It's reported to be flakey at 100M. They are bit-banging the phy from gpio pins.

Halfway around the world.

The RP2040 is good at bit-banging as the M0+ has direct access to the i/o pins from the cpus. There are also programmable state machines for more complex i/o. Some of the other Raspberry PIs are of course much faster. I can easily download files from an http server to a Pi4 at about 900Mbit/s. The Compute Module 4 is a very nice device for embedded applications, but they are hard to find at the moment. They have a single lane of PCI-e available for external use. There is a huge matrix of variants with different combinations of memory and WiFi. However, if the RP2040 will do what you need it has the huge advantage of good availability. The processor had stock levels of around 1 million when I last looked and the Pico boards are also readily available. There is now a WiFi version. I recently bought a Netgear MS108EUP 2.5Gbit/s PoE++ switch. The lowest advertised speed is 100Mbit/s. I also have a QNAP QSW-2104-2S switch with

2.5 and 10Gbit/s ports. Again, the lowest advertised speed is 100Mbit/s. I will check whether these switches secretly support 10Mbit/s as well. John