Questions about the electrical implementation of Ethernet; ask another Stack Exchange for software or protocol questions. Specify the speed as 10/100BASE-T is somewhat different from 1000BASE-T, apart form the speed. Those are copper standards; Ethernet over fiber optical cable is also defined.

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1answer
57 views

Current over CAT6 ethernet cable

How much current can a CAT6 cable reliably handle? I want to use 3 of the cores for +5V and 3 cores for GND. I'm wondering at what current I need to think of another power solution.
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0answers
41 views

Arduino won't connect to Internet

I recently bought an Arduino Ethernet shield which I want to use with my Arduino Duemilanove ATmega 328. I connected my ethernet shield with my Arduino board and connect shield with my router using ...
0
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1answer
23 views

Why should link status=down when speed mismatch?

For any internetworking equipment, link status (layer 1)=down when speed is mismatch between 2 ethernet interfaces. Does communication cannot happen when speed is mismatched? If yes, why? Is there any ...
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0answers
58 views

Carrier Wave in Wired Data Networks

I know this must be trivial for many... Which are the main reasons why line data is not modulated/demodulated in normal enterprise wired networks (in the sense that discrete voltage levels are used)? ...
-3
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0answers
29 views

W5300 verilog or VHDL driver [closed]

I would like to have a LAN interface between FPGA board and my PC via this a WIZnet W5300 IC. Could anyone help me write control module or it's state machine in verilog or VHDL?
11
votes
1answer
1k views

Why is Ethernet not intrinsically safe?

I understand from a training session that ProfiBUS is considered intrinsically safe, while ProfiNET is not. Some googling indicates that ProfiNET can never be intrinsically safe, because Ethernet can ...
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3answers
63 views

Maximum cable length for 5V or 3.3V I2C, UART, or 1-wire signals over Ethernet and how to increase it?

I know similar questions have been asked before (Maximum cable length for 3.3V UART signals) but I would like to know the answer more specifically for a hobbyist. I've been experimenting connecting ...
1
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0answers
46 views

Speed of my internet connection [migrated]

When I plug in my computer to the "World wide web" with an Ethernet cable, is its length affects my speed of internet? I am not sure if its the correct forum for this question so refer me if needed.
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votes
1answer
28 views

Ethernet NIC architecture: Function of loopback circuit

I want to make sure my understanding of the function/the needs of loopback to detect collision is correct. There is frame to transmit from Ethernet controller. TX transmits to wire, loopback and ...
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0answers
31 views

Home ethernet connection problem [migrated]

I had a technician wire my house with ethernet cables which all connect to a TPLink hub. My hope was to have a wired internet connection in a few of the rooms. The cables are around 10 meters each. ...
0
votes
2answers
60 views

Virtex 6 ethernet

I have tried to implement the example design which provided with "Virtex 6 Embedded Tri-mode Ethernet MAC wrapper v2.3" in Core generator,on virtex 6 development board(ML605) When I program it on the ...
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0answers
66 views

How to get Ethernet cable into a small enclosure

I have a project with a Raspberry Pi in a small enclosure that is in a weather-protected outdoor location. I currently have power and gpio signal cables entering the enclosure through grommeted ...
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0answers
64 views

VGA to Ethernet [closed]

I am using VGA to Ethernet Frame grabbers for my job. I need a VGA to Ethernet frame grabber which is like the Epiphan's product on the internet(it can be easily found when searched in the internet). ...
3
votes
2answers
289 views

Cat5 wire connector does not appear to be continuous

I'm trying to use a cat5 network cable and connection jack (what I'm calling the female version of cat5) as a way to quickly connect/disconnect 8 wires for an electrical project. I bought a few cat5 ...
1
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0answers
54 views

Ethernet communication [closed]

I want to make a simple program which achieves Ethernet communication. Specially I will try to connect this ENC28J60 Ethernet LAN Network Module and make a simple real time monitoring application ...
2
votes
1answer
116 views

Is it possible to inject USB signals (with power) through Ethernet?

I'm just curious whether it is possible to inject USB through Ethernet in a way like POE does but with the additional data lines USB needs. As per my understanding Ethernet (at least the slower ...
0
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0answers
23 views

Link integrity test pulse vs carrier signal

Ethernet uses a refinement of ALOHA, known as Carrier Sense Multiple Access (CSMA), which improves performance when there is a higher medium utilisation. When a NIC has data to transmit, the NIC ...
1
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0answers
65 views

How to get an ENC28J60 to work?

For starters: Yes I know I'm about to reinvent the wheel with the following task ahead. I want to create my own library for the ENC28J60 for an AVR (ATMEGA1284P). So I've been browsing the net for ...
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0answers
47 views

Converting Ethernet hardwire signals to Wifi using RMII interface and embedded bridge module

I have an embedded sensor that has an Ethernet RJ45 cable/connector, which include Tx+, Tx-, Rx+, and Rx- signals that I need to convert to wireless. I need to embed it with the sensor and it needs ...
0
votes
1answer
41 views

What is 'valid signal' that router receives to indicate physical status is 'up'?

If the Ethernet interface has a cable connected and is receiving a valid signal, the physical link shows an “up” status and there are no active alarms or defects. If the interface is not connected ...
2
votes
1answer
66 views

RMII MAC side routing and signal integrity

I have some signal integrity and EMC questions. In my board LPC1768 RMII interface is connected to LAN8720. Because of pin locations some RMII signals must go through bottom layer. This is a four ...
0
votes
2answers
93 views

What is “M” in Hartley's law?

If Hartley's law is: $$ C = 2 B \log_2 M $$ I know this equation is part of calculating the capacity of a channel. I also understand that: \$C\$ is the digital bandwidth, in bits/second \$B\$ is ...
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votes
0answers
49 views

Connect two embedded devices with USB host with Ethernet?

I need to connect two microprocessors that only have USB host, not OTG or client. Obviously I would like to connect them as directly and quickly (ie 10's of Mbit up to 100) as possible. A USB to ...
4
votes
3answers
104 views

Can a barrel shifter be done combinatorially?

I was told that 66b/64b encoding in 10Gb Ethernet (10GBASE-R) requires a one-cycle barrel stage, which adds a necessary one cycle to the theoretical terminal latency. The Wikipedia page on barrel ...
0
votes
2answers
120 views

What happens if I accidentally connect an Ethernet device to my 1-wire bus?

I have built a networked temperature sensor by connecting several DS18B20 temperature sensors to my Arduino. I've tried to visualize the setup with this schematic (sorry if this doesn't make any ...
4
votes
2answers
102 views

Two analog power planes for same voltage

I'm designing a board with LAN8720 and LPC1768. LPC's ADC and LAN's magnetics connections require analog 3.3V power. Should I separate these two analog power planes with a ferrite as I separate it ...
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0answers
39 views

Reading Ethernet Link Pulse

I want to read the link pulse of an ethernet connection (connected to hub one end and unconnected on the other) through an oscilliscope. Eventually I want to detect the pulse using a microcontroller ...
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votes
2answers
133 views

Unmanaged Ethernet switch silicon? [closed]

I need to add an unmanaged Ethernet switch circuit to my PCB, but I can't find any usable silicon, not even with 100BaseT. Am I missing something? I don't want to have to connect it to a ...
0
votes
2answers
94 views

Ethernet signals

I have an end of an ethernet cable but I don't know where it goes. I want to see if it is connected to a device at the other end. Looking at the pinout you have a TX+/TX- and an RX+/RX- pair of ...
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0answers
60 views

Ground Plane, Bypass Capacitors and Differential Pairs

I've placed a KSZ9031MNX Ethernet PHY on my board, and am now trying to get power routed to it. The digital side will merely be annoying to do, I think, but I'm at a complete loss on the analog side. ...
0
votes
1answer
75 views

Collision detection on ethernet coaxial cable

On ethernet coaxial cable, how collision is detected by the sending device? I was told by someone that it is related to high electrical current and the difference between the sent frame and the ...
0
votes
0answers
88 views

Read and write FPGA registers via USB or Ethernet

I'm working on an FPGA project on an Atlys Spartan 6 board. I'm programming it in VHDL. I have two 32 bit registers, one for output, the other for input. I need to be able to, respectively, read and ...
1
vote
1answer
115 views

AVR Embedded Webserver + Time

I have the task of implementing an embedded webserver (using ATMega328). Broadly, the system would provide the following functionality Allow user to change system parameters using the web interface ...
0
votes
1answer
51 views

L2 Bridge over Asynchronous Serial line [closed]

I am using pppd (in linux) to send ethernet data over a serial line to another computer. How can I preserve L2 headers while sending Ethernet frames over serial line? It seems the ppp protocol sends ...
0
votes
1answer
85 views

Ethernet chip with integrated tcp/ip stack [closed]

I would like to ask what Ethernet chips are popular for an embedded webserver project. Features needed ... integrated tcp/ip stack support ntp protocol php support Basically the main purpose of ...
0
votes
1answer
26 views

Trouble bridging connection between my Pi and my laptop's WiFi

I have been trying to get this working for a while now and still no luck. I have Googled and Googled till my eyes hurt and everything I try won't fix it. I have sharing disabled on both connections, ...
-2
votes
1answer
72 views

Chat through serial port [closed]

I have completed software part but need help in hardware side. We are given few components and asked to do communication (chat) between two PCs. Components list is: USB to TTL converter Ethernet ...
1
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0answers
58 views

Wake On LAN to PMIC

I'm a connecting a WOL interrupt port of the PHY (an open drain port) to the ON-OFF port of the PMIC of my device. The idea is do a reset of the PMIC and then I'm going to turn on the MCU from a ...
0
votes
2answers
165 views

Why is propagation delay of ethernet cables unaffected by cable length?

I did some searching on how propagation delay in ethernet cables is affected by the cable length. The answer seems to be that the delay is negligible until the cable length reaches a kind of threshold ...
2
votes
2answers
145 views

Problem with Ethernet PHY

One of my clients is experiencing problems with a SMSC LAN8710A PHY that is connected to a Xilinx FPGA. The Ethernet link works perfectly when the board is connected to my MacBook or to my office ...
1
vote
1answer
176 views

How important is the number of cores in RJ45 jacks with magnetics

While searching for RJ45 jacks with magnetics (MagJacks) in Digikey, we found that there is a selection criteria which says "Number of cores per jack". Though we have been using MagJacks previously, ...
0
votes
1answer
79 views

Vitesse VSC8221 Ethernet PHY for Media Converter Application

I'm currently designing a media converter board using Vitesse VSC8221. Just as an FYI, the documents for this product are all available at the product page. No NDA is required. When I say media ...
0
votes
0answers
65 views

W5100 Ethernet Module never recieves any data

I am using W5100 Ethernet module (same as Arduino Ethernet module) with Atmega16A to connect to local server (I.P.: 192.168.1.146 Port: 80) created using XAMPP on my own PC. I am able to establish a ...
0
votes
1answer
133 views

RJ-45 with magnetics transformer (Ethernet port) connections

I am working on circuit having RJ45 connector with built-in magnetics transformer. The schematic diagram of mentioned circuit shows following connections with Rj45 magnetics connector. At first I ...
0
votes
1answer
96 views

Make simple 3 port ethernet switch/Hub [closed]

How can I make a simple cheap 3 port Switch? I have 30 10-base low speed Ethernet devices and I want to connect them together, how can these devices connects together with simple Bus topology? ...
3
votes
2answers
470 views

Homemade ethernet hub not working with three computers [closed]

I am trying to connect three computers in one network. I have connected the wires like the photo. I works with two computers but not three computers at the same time. For example, let's name the ...
2
votes
2answers
95 views

Ring Topology Ethernet Backplane - 3 Port 1GbE Switch

I'm doing a thought experiment/napkin design for low cost cluster processor system. Some low cost, high MIPs CPUs chained together on a backplane. My first thought for a backplane is ethernet, because ...
0
votes
1answer
94 views

Best solution for making a LAN with 2 untwisted lines

I need to provide a best solution for establish a LAN for old train carriages in order to transfer low quality video surveillance data. Only existing lines are 2 wires untwisted throughout all ...
0
votes
0answers
15 views

How do I connect my AKM Servo Motor through the Kollmorgan WorkBench?

I have an AKM21C servo motor from NI, connected to a AKD P00306 drive, which is connected to a UMI-7774 board. And I'm trying to connect it through Kollmorgen Workbench, but it doesn't detect a ...
3
votes
2answers
127 views

125 MHz parallel bus in a double 2.54mm header

I have a BeMicro CV low cost dev board from Altera. It features a Cyclone V. FYI: Schematics and gerber here They routed impedance controlled differential lines to some dual 2.54mm standard headers. ...