Connection Issue


I want to connect a female Ethernet to pins on 8 port relay. Because there are 10 pins I have to use 2 Ethernet ports. I was going to just punch down jumpers into the Ethernet port but those cables are too big. So I have a few potential solutions and was wondering if others have any.

  1. Splice Ethernet to jumpers
  2. Use Pliers to smash jumper wire before trying to punch down (not sure if this will work)

Thanks, -Jared

I don't quite follow what you're trying to achieve. I think there is a terminology barrier going on here. What do you mean by jumpers? punch down? smash jumper wire?

What are the 10 connections you have? Where do you want them to end up? How does ethernet fit into the equation?

On a female Ethernet connection there is a punch down block or terminal that Ethernet cable is "punched" into. By jumpers I meant the jumper wires going into a breadboard. So female jumpers fitting over the male pins for the relay side then on the Ethernet side (where the punch down block is) I was thinking of trying to smash the jumper cables with pliers or putting Ethernet cables in and then splicing those to the jumper cables.


What is the size of your jumper wires? You can use CAT 6 plugs which able to fit cable size AWG 23-26.

I still don’t quite get you. I have a feeling you may be talking about a MALE RJ45 connector:

Not the female one. (The female one is a socket - it has a “hole”…)

I would personally get a female RJ45 socket and solder that to jumper wires, then you just plug in the RJ45 ethernet cable without worrying about wire dimensions, crimping (what you call “punching down”), etc.

I think this is the kind of IDC RJ45 socket that you see in wall-mounted ethernet sockets.

The standard ethernet solid cored wire is what you need to fit the IDC block, but this will be too thin to work with standard female headers, note.

This wire is obtained but cutting off a length of CAT5/6 cable, stripping off the jacket and extracting the wires!

Ah, yes, of course. Those puppies. Been a while since I had to fit any of those...

So yes, you definitely want some cat5 cable (solid core, not stranded "patch leads") and punch that into the IDC terminals of the socket. Then I'd be inclined to solder the other end to some other connector you can connect easier to.

Either that or use RJ45-to-DB9 adapter housings, so you can solder your own wires to DB9 plugs:

You could even have DB9 face plates instead of RJ45: (yes, I know that is populated by DB15, but it illustrates the point).

What are you trying to do? This seems overly complicated if you just want to connect wires and I'm pretty sure Ethernet doesn't work as a bus.

mirith: What are you trying to do? This seems overly complicated if you just want to connect wires and I'm pretty sure Ethernet doesn't work as a bus.

Ethernet is just a networking protocol. It has no concept of buses or anything. What people think of as "ethernet cables" are actually Cat5 / Cat6 / Cat6e (etc) RJ45 cables. The topology (physical layer) they work with is 10Base-T, 100Base-TX, 1000Base-TX etc., in a star configuration. This is one part of the Ethernet standard, that happens to utilise the aforementioned cables.#

Before those came 10Base-2 Ethernet - that was 10Mbps and used a 50? coaxial cable arranged in a bus configuration.


"What is the size of your jumper wires? You can use CAT 6 plugs which able to fit cable size AWG 23-26."

Impressive you know the gauges of Cat 6 cabling


I am talking about the female connector. What I call punching down refers to the connection method on the back of the socket. You use a punchdown connector to attach ethernet wires to it. Not crimping ethernet wires into a male socket. Same as a punchdown bar (might be what its called) that is in a network closet or data center.


That's the problem I'm having. Imagine going from 10 female pins couple inches over to a female ethernet socket.

I thought I had a simple solution but wires not fitting have made it complicated. I have a sainsmart relay which has 10 male pins. Male sticks out like a male limb (one that females don't have). To a female ethernet port, or technically a 8 port twisted pair jack (you forgot 10baseFiber) So pins from the sainsmart to punchdown on back of ethernet jack. To make this connection my initial thought was just use some jumper cable instead of ethernet. (Female jumper cable side to sainsmart relay and other side to punchdown and snip remaining part) 10 cables = 2 female ethernet jacks using jumper cables. Well jumper cables don't work in ethernet jack (to wide). So looks like splicing ethernet to jumper cable is way to go. Unless someone has other idea. I made something like this except the Arduino isn't in the same container so to link that with the Arduino I was just gonna use 2 ethernet cables (2*8strand cables)

... non-IDC RJ45 sockets?

And I didn't miss out 10Base-F, nor 100Base-FX or 100base-FX - I wasn't including fibre in this diet as it was irrelevant.