Ethernet-USB Cable

  • Thread starter Thread starter Alek Trishan
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Paul has written on 6/1/2014 4:45 PM:
It would be used for adding Ethernet, to a computer
with no expansion slots.

You could use it, say, for making a router out of
an old computer.

And ones like this, have no bottlenecks. I didn't know
if they made any USB3 ones, but they apparently do.

http://www.newegg.com/Product/Product.aspx?Item=N82E16812232044

Paul

The ones I have have an Ethernet plug (not a jack) on the end. What
would that be good for?
 
Alek said:
Paul has written on 6/1/2014 4:45 PM:

The ones I have have an Ethernet plug (not a jack) on the end. What
would that be good for?

If it was Ethernet, you could hook one computer to another.
But it might require a crossover Ethernet cable.

Just be certain to verify what you see
on the dongle is RJ45 and not RJ11. If you
see RJ11, that's the telephone one, and the
dongle would be for a dialup modem connection
to a phone line.

http://en.wikipedia.org/wiki/RJ45_(telecommunications)#RJ45

The RJ11 has six pin positions, while the RJ45
is eight pin positions. A 10/100BT Ethernet only
needs four pins (as two twisted pairs) while 1000BT uses
all eight (as four twisted pairs).

If the thing says Ethernet right on it, then
that would remove the uncertainty as well.

Paul
 
Alek Trishan wrote on 2014/06/01:
Paul has written on 6/1/2014 4:45 PM:

The ones I have have an Ethernet plug (not a jack) on the end. What
would that be good for?

That the device (e.g., router) into which you plug the Ethernet male
connector and the device (e.g., computer) into which you plug the USB
cable have to be as close together as is the length of cable between the
Ethernet male and USB connectors on that adapter.

For example, the Ethernet male connector on the adapter could go into a
RJ-45 plug on a router while the USB end of the adapter could go into a
USB port on a computer. Another example is a printer with Ethernet
support (i.e., network-able printer). You could plug the adapter's male
Ethernet connector into the printer's RJ-45 Ethernet port and the USB
connector into your computer. The printer is networked but only to that
host (so you would have to share the device with other hosts to
"network" it to those other hosts).

Generally such devices, like the one shown at Newegg, are called gender
changers. With cables, the connector types are different at each end.
This is an active (powered) device which not only changes connector
types but also the hardware protocol. What connectors are on these
depend on the gear to which you connect them.

It's possible the adapter you have was made for use with a specific
device. For example, the RS-232 (serial) cable that came with many
UPSes was not a standard serial cable but a specialized one with its own
wiring and pinout and where one end was marked "UPS" and had to be
connected to the UPS's RS-232 port and not the other way around and a
regular serial cable wouldn't work. To make sure the cable worked meant
you had to get their special cable, not some normal cable from anywhere.

There is no brand and model number marked on your gender changer? Does
it look like this?

http://www.newegg.com/Product/Product.aspx?Item=N82E16812705330

That has the RJ-45 male end but also has a USB female end. When you
said "USB", you didn't say what type of connector.
 
Paul has written on 6/1/2014 6:02 PM:
If it was Ethernet, you could hook one computer to another.
But it might require a crossover Ethernet cable.

Just be certain to verify what you see
on the dongle is RJ45 and not RJ11.

It's definitely RJ45. It's too big for a telephone jack and snaps in to
an Ethernet jack.

So, what do you think? I have no idea when and where they came from.
 
VanguardLH has written on 6/1/2014 6:24 PM:
Alek Trishan wrote on 2014/06/01:

That the device (e.g., router) into which you plug the Ethernet male
connector and the device (e.g., computer) into which you plug the USB
cable have to be as close together as is the length of cable between the
Ethernet male and USB connectors on that adapter.

Isn't that true for every cable? I'm obviously missing your point here.
For example, the Ethernet male connector on the adapter could go into a
RJ-45 plug on a router while the USB end of the adapter could go into a
USB port on a computer.

Would that then serve as a network connection for the computer?
Another example is a printer with Ethernet
support (i.e., network-able printer). You could plug the adapter's male
Ethernet connector into the printer's RJ-45 Ethernet port and the USB
connector into your computer. The printer is networked but only to that
host (so you would have to share the device with other hosts to
"network" it to those other hosts).

I'll have to see if my printer has an Ethernet jack.
Generally such devices, like the one shown at Newegg, are called gender
changers. With cables, the connector types are different at each end.
This is an active (powered) device which not only changes connector
types but also the hardware protocol. What connectors are on these
depend on the gear to which you connect them.

This is definitely not what I have.
It's possible the adapter you have was made for use with a specific
device. For example, the RS-232 (serial) cable that came with many
UPSes was not a standard serial cable but a specialized one with its own
wiring and pinout and where one end was marked "UPS" and had to be
connected to the UPS's RS-232 port and not the other way around and a
regular serial cable wouldn't work. To make sure the cable worked meant
you had to get their special cable, not some normal cable from anywhere.

Aha! This may be the cable that connects my UPS to my computer (for
whatever purpose -- monitoring the UPS, perhaps?)!
There is no brand and model number marked on your gender changer? Does
it look like this?

http://www.newegg.com/Product/Product.aspx?Item=N82E16812705330

Definitely not.
That has the RJ-45 male end but also has a USB female end. When you
said "USB", you didn't say what type of connector.

It's a type-A male.
 
Alek said:
Paul has written on 6/1/2014 6:02 PM:

It's definitely RJ45. It's too big for a telephone jack and snaps in to
an Ethernet jack.

So, what do you think? I have no idea when and where they came from.

OK, say you have a desktop computer, and you normally
run an Ethernet cable to your modem/router for broadband.

You could unplug the regular Ethernet cable, connect the
USB to Ethernet, and run the connection that way.

Before:

computer --- internal_Ethernet --- Ethernet_cable --- router

After:

computer --- internal_Ethernet --- X
--- USB_to_Ethernet --- Ethernet_cable --- router

As long as there is just one path wired up, the OS will
figure out how to get there. I've never used one of those
USB to Ethernet things, and don't know what it takes for
a driver. If the USB standards people defined a standard
"class" for it, it's possible the Microsoft OS already
has a driver to use with it.

Paul
 
Alek Trishan said:
The ones I have have an Ethernet plug (not a jack) on the end. What
would that be good for?

There at least used to be range extenders for USB which used ethernet
for the long haul. I don't know if those are still around but I guess
your cable could be part of such a system. Although it seems strange,
why go with a proprietary cable?
 
Alek Trishan wrote on 2014/06/01:
VanguardLH has written on 6/1/2014 6:24 PM:

Isn't that true for every cable? I'm obviously missing your point here.

Some adapter just have the connectors and you add the cable in between,
so the length is whatever for cable you choose. In case your
description omitted a cable that was attached, like a cable to the USB
connector, then that might be the intended length although you could add
another cable to extend the length. More connectors means more signal
attenuation, more chances to break, and more connections with reduces
the reliability of the overall connection from end to end. If the
adapter came with its own length of cable, try to use just that length.
Would that then serve as a network connection for the computer?

It could but a short cord probably means it was meant for something
else, like maybe a wireless access point that then uses a USB port for a
hardwire connect to an RJ-45 port on the router.
Aha! This may be the cable that connects my UPS to my computer (for
whatever purpose -- monitoring the UPS, perhaps?)!

From what I've seen, the USB connection from computer to UPS uses a
standard USB cable. It may have type A, type B, or a mix of the two
type of connectors but it's all a standard USB cable. There is no
signalling wire changes. It's the RS-232 (serial) cable that often is a
special cable with wiring different than RS-232 pinouts where you have
to use the end marked "UPS" at the UPS and the other end goes to a
RS-232 port on the computer.

It's possible your UPS has network connectivity. Yet if you already
used the hardware RJ-45 Ethernet port on the computer (or a wireless
access point) then you need to use USB to the USB-to-Ethernet adapter to
connect to the Ethernet port on the UPS.
Definitely not.

Then you might want to take a photo and upload it to a pic site and
share the URL to it so we can actually see what you're asking about.
It might provide a clue as to what it is for ... maybe.
 
VanguardLH has written on 6/2/2014 4:53 AM:
Alek Trishan wrote on 2014/06/01:


Some adapter

Um, I DO NOT HAVE AN ADAPTER!!! (Sorry about the yelling.) I have a CABLE.
Then you might want to take a photo and upload it to a pic site and
share the URL to it so we can actually see what you're asking about.
It might provide a clue as to what it is for ... maybe.

I don't know how to make this more clear.

I have an otherwise cable.
At one end is an Ethernet plug.
At the other end is a type-A male USB connector.
 
Alek said:
VanguardLH has written on 6/2/2014 4:53 AM:

Um, I DO NOT HAVE AN ADAPTER!!! (Sorry about the yelling.) I have a CABLE.


I don't know how to make this more clear.

I have an otherwise cable.
At one end is an Ethernet plug.
At the other end is a type-A male USB connector.

OK, I found a picture of one. Please verify this is it.

http://fdisnorthamerica.com/cable-220-2442-00.html

The accompanying text says:

"Application 4800 to POS"

The POS would be some sort of Point Of Sale equipment.
The 4800 is either a part number, model number, or
implies 4800 baud or something.

Electrically, this makes no sense, but that's never
stopped people from making cables before.

Paul
 
Alek Trishan wrote on 2014/06/02:
Um, I DO NOT HAVE AN ADAPTER!!! (Sorry about the yelling.) I have a CABLE.

One end is USB. The other end is RJ-45 Ethernet. There has to be a PCB
inside the cable or at the ends /to do hardware protocol conversion/.
That's if it really does switch from USB to Ethernet protocols.

If there is no active converter inside the cable or inside the connector
ends then it is for some special use. Someone decided to use a RJ-45
jack as a USB port or a USB port as an RJ-45 jack. I haven't seen one
of those probably because it doesn't make sense to have this setup since
a USB port would be as easy to install as an RJ-56 jack or visa versa.
A specialized adapter (no hardware protocol conversion) has someone
being mean-minded and greedy by forcing you to use their special cable
instead of a standard one. Instead of buying a $4 USB cable, they make
you buy their $30 custom "cheat-em-and-how" cable.

By the way, the term "adapter" still applies. You've never seen a
Y-adapter for Molex connectors from a PSU or the Molex-to-SATA power
adapters? Or a SCSI adapter cable that changes from a Centronics-50 end
to a D25P or mini-50 end? Your video card (if not OEM or white box)
didn't come with some adapter cables, like VGA out to RCA? Sometimes
adapters are blocks or dongles to which you connect cables or the
adapter can include a length of cable. Inside the adapter block or
dongle are wires from one connector to the other. Well, an adapter cable
is just a set of wires from one connector to the other, too. In fact,
you might not have room for a adapter block or dongle because it would
block other connectors (e.g., backpanel of system case) so the dongle is
elongated by adding a length of cable. "Adapter" does not preclude a
length of wiring (cable) to separate the connectors.
I don't know how to make this more clear.

I have an otherwise cable.
At one end is an Ethernet plug.
At the other end is a type-A male USB connector.

Okay, so you won't show us. From your terse initial description, it
seemed an adapter that converts between hardware protocols but you say
no (although the PCB could be tiny and inside a connector shroud). You
claim it's just a cable but with mismatched hardware protocol-type
connectors on each end. That you don't see a big bulge for a PCB
doesn't mean there isn't one inside, like at the connector ends. If the
shroud around the connector is short, like ending almost right at the
end of the connector where the cable exits, and there is no bulge in the
cable then it is probably a passive cable. If there is a bulge or one
of the connector ends is elongated then there could be a PCB there.

USB has 4 pins. RJ-45 has 8 pins but only 4 may be used (for a network
connection). If the RJ-45 plug is clear, you might see if less than 8
wires go to its 8 pins. You could run a continuity test between the
pins to see which USB connector pins go to which RJ-45 pins. If more
than 4 pins on the RJ-45 are connected to wires then there might be some
splicing inside the cable or multiple wires to a pin at the connector so
one, or more, USB pins go to 2, or more, RJ-45 pins; however, if there
is a PCB inside for hardware protocol conversion, a continuity check on
the unconnected cable (so no power from USB port) won't show which pin
is logically connected to which other pin.

Like Paul says, anyone can wire a mashup of different connectors however
they want. If current draw were small, I could use either a USB or
RJ-45 jack for a 120 VAC wall jack (the proximity of the pins would make
this dangerous). I could use an RJ-45 jack in place of an RJ-10 jack
for a telephone wall jack (although the telephone's RJ-10 jack will fit
loose inside an RJ-45) which has been done in some offices (occupants
don't know which is the phone jack versus network jack unless labelled
and hopefully the cable crew didn't reverse them). I could use a USB
cable as an antenna feed. However, in each case, I'm misusing the
connector type by not employing it for the hardware protocol for which
it is commonly used and originally intended.

So we're back to my other post at the paragraph starting with "It's
possible the adapter you have was made for use with a specific device."
While I've seen custom cables (you must use theirs) for a UPS, the
connectors at each end were the same; i.e., it was RS-232 (DB-9) at each
end or USB at each end, not a mismatch of connectors typically used for
differing hardware protocols.

Since you're not using this cable, it isn't important to any of your
current setup(s). It might be something left in your parts drawer, like
all those /adapter/ *cables* that came with your video card, for some
hardware you got rid of awhile ago.
 
I found it!

It's an APC 940-0127B USB/RJ45 UPS cable, used in some older battery
backup systems (power outage protection) to communicate with monitoring
software on whatever PC it might be plugged into.

Thanks for all your suggestions.
 
Alek Trishan wrote on 2014/06/02:
I found it!

It's an APC 940-0127B USB/RJ45 UPS cable, used in some older battery
backup systems (power outage protection) to communicate with monitoring
software on whatever PC it might be plugged into.

Thanks for all your suggestions.

Wow, I'm somewhat surprised that APC would employ a Frankencable.
 
VanguardLH has written on 6/2/2014 6:52 PM:
Alek Trishan wrote on 2014/06/02:


Wow, I'm somewhat surprised that APC would employ a Frankencable.

Why is this a "Frankencable"? Is there electronics in it somewhere?

OTOH, a straight USB cable would seem reasonable.
 
Alek said:
VanguardLH has written on 6/2/2014 6:52 PM:

Why is this a "Frankencable"? Is there electronics in it somewhere?

OTOH, a straight USB cable would seem reasonable.

It's a Frankencable because it can cause havoc if
plugged between two pieces of equipment it is not
intended for. Notice how none of us were ready for it
in this thread...

Ethernet is transformer isolated. Each of two twisted pairs
would terminate in a "dead short" at DC frequencies. If the
USB VBUS and USB GND were on a twisted pair, they would
short out, and the resettable fuse on the motherboard
would open. If VBUS and D+ were on twisted pair and
GND and D- were on the other twisted pair, and you plugged
into Ethernet, maybe the interface would survive that. But
twisting the signals that way, probably isn't the best
for actual data transmission. You certainly wouldn't want
the USB pad drivers, attempting to drive into that.

I don't know how "Safe" that cable is, and frankly,
don't want to waste the time researching the possible
outcomes. You could leave the cable dangling off the
UPS box, as a reminder of what it belongs to.

Paul
 
Alek Trishan said:
What are the applications for a Ethernet-USB cable?

There are a few UPSes (APC made a couple) that use RJ45 on one end, and
USB on the other. Note that it's not ethernet (although it uses the same
end that ethernet uses), so the devices are not networkable.

You'll see point of sale gear using similar (or USB to HDMI -- Again,
not really HDMI, just a convenient proprietary design)
 
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