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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Problem in connecting two BBB via Ethernet!

I am experiencing problems while connecting two BBB(beagle bone black) boards via their ethernet ports. I have seen some reports on problems regarding to the PHY on BBB not detected on power-on. BUT ...
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1answer
60 views

What frequency does 100G Ethernet work on and how does it work? [closed]

Is the frequency 2Ghz and does it use many channels over OFDM? Is that why it's so expensive? EDIT: forgot to mention that this is over copper, not fiber (fiber operation is described on Wikipedia)
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25 views

lwIP initialization hangs when configuring TEMAC

I am working on a my master thesis, designing an FPGA solution, and have run into a very resilient problem. I will try to provide as much information as possible, in the hopes that someone might have ...
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0answers
22 views

Things That Affect NIC Cards' Performance? [migrated]

Folks, I have a laptop and a tower. And I use EtherCAT (through Ethernet port) on both. But I notice that if I unplug my cables on the tower, I loose a lot of frames, where as in the laptop I may not ...
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1answer
32 views

Converted from ms per int to Hertz [closed]

I am trying to convert from ms per int to Hertz. I have found that my system takes 0.2313ms to transfer one 32 bit interger. Based on this answer Difference between Hz and bps I have divided my ...
3
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1answer
39 views

Is my Bob Smith termination valid for Ethernet 100Mb/s?

This is my first ethernet circuit, and I am a noob in differential signal lines. That is why I want to learn with a "simple" circuit. I use the reference schematics from the LAN9512 usb to ethernet ...
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2answers
85 views

Sending PWM signals down cat5 cable

I working on an LED lighting project where I will be installing 20 boxes in a space, each containing 4 LEDs (RGB and IR.) I want to connect all of these boxes to central board which will drive all of ...
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1answer
44 views

Problem with Ethernet controller ENC424J600

I have recently produced a number of prototypes using the Microchip ENC424J600 Ethernet IC. I can't a full circuit diagram as this is a commercial product but I have reproduced the relevant part of ...
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1answer
27 views

In PoE: is alternative A compatible to all PDs?

I am currently designing a PoE plus device. I'm using 1G speed and currently following alternative A configuration (data pairs 1/2 and 3/6). Question is: Can all Powered Devices (PD) support ...
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3answers
82 views

What can cause an oscillator output voltage to go higher than expected?

I am currently testing a 50MHz 3.3V CMOS oscillator in my circuit, which is connected to two pins/loads - MCU pin and Ethernet PHY pin. The oscillator is rated for 15pF output load, which I could be ...
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0answers
40 views

high-speed interface for robotics vision system cameras [closed]

I need to design a high-speed, high-resolution camera for a robotics vision system, and need to choose the appropriate interface and cable standard between camera and PC. Typically 4 cameras will be ...
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0answers
38 views

Connecting multiple ethernet devices with switch directly (bypassing transformers)

As the title states, I'm interested in connecting several ethernet devices with network switch directly, without the need of transformers that are inside the RJ45 onboard connectors. I've seen this ...
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0answers
25 views

Using W5100 without transformers magnetics

I would like to make a transformeless connection between an ethernet phy to a w5100. So here is my question: Any PHY can be connect without transform ? (just using a capacitive coupling). If is not, ...
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1answer
48 views

Transparent Wi-Fi module with RMII input

I need to convert a Ethernet-connected embedded project with wireless connection. I'm looking for a low-cost (main constraint, less than USD $15) and most open-source/-hardware possible Wi-Fi bridge ...
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1answer
84 views

How many pairs of wire to use for Power over Ethernet?

I have a custom setup to supply power over Ethernet cables. I used a pair to connect to a telephone and another pair for power. The device needs 12 Volts at 0.5Amps to run. In normal setups, which ...
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1answer
44 views

stm32f207 ethernet interrupts problem

I installed RTX (rtos from Keil) and Ethernet library from STM for stm32f207 MC. I configured UDP using ethernet + LwIP as in examples from STM. Without RTOS UDP works fine. I send and get packets ...
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1answer
59 views

SFP vs LAN port [closed]

From a board design standpoint, What are the categories to consider when picking between an SFP and LAN port. This is to be used as a 1GE management data path so regarding data rates both options ...
2
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1answer
332 views

Using Ethernet cables cable for sensor wiring

I'm exploring the pitfalls of using an Ethernet cable for extending sensor cabling. The term Ethernet cable is used ambiguously on purpose to denote an "easily available 8-wire cable whose category ...
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1answer
46 views

RJ45 color code for cable with no-standard colors of T568D

I have an UTP cable with the colors: white-yellow, white-black, white-red and white-purple. I would like to use this cable as an Ethernet cable. I know the color code to make straight through Ethernet ...
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0answers
36 views

Requirements on dielectric strength and isolation between the conductors in an Ethernet transmission line with PoE

I am trying to find out what the requirements are on dielectric strength and isolation between the conductors in a Gigabit Ethernet transmission line. A first place to look would of course be the ...
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1answer
64 views

Can a same phy be used for IPV6 and IPV4?

Currently I am using LAN8720 from microchip in my device for IPV4 network?Can same PHY work with IPV6 network? If yes the why? and if no then what can anyone suggest me a decent chip for it? Thanks
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1answer
57 views

DC Resistance of Cat5e Cable and Type 2 PoE

I see that the PoE Type 2 standard assumes a maximum loop resistance of 12.5 Ω/100 m, but cat 5e is specified to have maximum loop resistance of 18.8/100 m Ω. Does this mean that PoE type 2 is not ...
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2answers
98 views

Convert BNC to Ethernet to Coax/HDMI

I need to make a cable run of approximately 150 feet. The source is a security camera box and the destination is a large ~42" television with all the basic hookups. The source box is in a room right ...
3
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1answer
166 views

Ethernet Pass Through over PCB

I'm working on a personal PCB design that will include ethernet pass through. Photo attached. Basically just ethernet in from a router, straight over the PCB to ethernet out which will go to a CPU. ...
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0answers
44 views

Broadcast traffic issue in PLC Ethernet network

The setting: network with about 10 PCs and 8 AB RSLogix 5000 PLCs. The issue: Everything is communicating OK, but I'm seeing what appears to be a lot of broadcast traffic within the network. It is ...
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3answers
325 views

How to Connect USB/Ethernet Shields to Chassis or Digital Grounds

I have a PCB with a few USB and RJ-45 Ethernet connectors on one side. I'm quite confused as to how exactly I'm supposed to be hooking up the SHIELD pins on them though. This is for a host device ...
2
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1answer
61 views

Adding Wi-Fi to a TCP/IP application that is already running with Ethernet

What to do if you have an Ethernet application that is already up and running with TCP/IP functionality and now you want to add Wi-Fi. Most of the Wi-Fi modules available have embedded TCP/IP stacks ...
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2answers
61 views

Put firewall hardware with ethernet ports between serial ports

I want to put a firewall hardware product between a RTU and PLC to block some Modbus function codes (e.g. write coil, read coil). (This firewall product is able to do deep packet inspection on Modbus ...
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0answers
52 views

Would you use Wiznet W5x00 in a commercial product? [closed]

I am working on a project where the product needs to be connected to the local network. For the products we use Atmel controllers (AVRs and ARMs). I choose Wiznet W5100 to be used in the prototype, ...
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0answers
44 views

Issues in schematic of Microchip LAN8720 & waveshare LAN8720?

For a project I need to integrate Ethernet with PIC32MX795F512L. For this I had two choices. I thought of purchasing this Waveshare LAN8720 module and directly ...
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2answers
66 views

Ethernet surge and protection

I recently worked with a client who experienced a transient on their Ethernet cabling. As you can see, no actual PCs were damaged, only the Ethernet cards of some machines. We don't know where the ...
2
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2answers
127 views

House wide automation network: CAN or Ethernet?

I am half-way through building my home automation system. As an electronic engineer/software developer a lot of this has been rolled myself from scratch and I will hopefully be starting to blog more ...
2
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1answer
101 views

May RJ45 connector with magnetics connected in series?

I have a dev board with a RJ45 connector which has magnetics integrated. I need put it into a case and mount another RJ45 on the panel, sadly I have only another connector which also integrate the ...
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1answer
55 views

Does the 802.3 Ethernet standard provide a recommended circuit design?

I have a project I am designing whose fundamental parts consist of sensors connected to a micro-controller. the micro-controller will then send the data out over an ethernet port using standard tcp/ip ...
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1answer
41 views

ethernet socket interface throught nail bed

I need to make a test nail bed for a board that has an Ethernet interface: in the bottom of the board there is access to the socket ethernet pins i could place test nails under the ethernet socket ...
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3answers
247 views

ENC28j60 ethernet interfacing with PIC18F4520 help needed

I am a newbie to ethernet controller. I need to use ethernet controller to send sensor data to our server using http get method. I went through ENC28j60 documentation and microchip's TCP/IP stack as ...
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2answers
98 views

Control door with RS232 or Ethernet relay

Our company use a fail safe electric bolt with a remote control for the entry door. It closes when the power is ON and vice versa. It does work normally but I want to make a hot button for the ...
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4answers
176 views

Can I use an ethernet module (or an USB connection) for light communication? [closed]

I'd like to transmit data (e.g. copy a file between two computers) at high speed via light. I found lots of examples around the web but mostly the speed is really slow because a serial connection ...
5
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2answers
173 views

Why didn't 1000BASE-TX gain more popularity than 1000BASE-T?

1000BASE-T uses all 8 wires in a twisted pair to both RX and TX at the same time. It does it using (what seems to me) a complicated process known as echo cancellation. Details here. 1000BASE-TX ...
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1answer
124 views

Ethernet switch controller chip

Recently I bought an ethernet switch controller based on the Realtek RTL8305NB chip. It was bought as a proof of concept for my robot. Unfortunately, the board is too big and I want to design my own ...
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3answers
82 views

How is a Twisted Pair's +-2.5v used to send a 1 or a 0?

This is a multi-part question that I'm asking as a follow on to this answer from my other question. I know 100BASE-TX transmits through a pair of wires, that are twisted around each other so that the ...
15
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7answers
3k views

What if there are an odd number of twists in a twisted pair cable?

I am not an electrician, or a student of the field. I am a Network Engineer with a curiosity bug and that has recently taken me to exploring cabling and Twisted Pair specifically. I say this to plead ...
2
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1answer
119 views

How to create Simple Web Server with Mbed and W5100 Ethernet Shield

I'm trying to develop a simple web server application with Nucleo f411re and w5100 Ethernet shield. My question is why the client.is_fin_received() function always returns 0. Why doesn't my web page ...
0
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1answer
55 views

Differential POE 1000base-t signaling through analog multiplexer

I want to make a test device which can route network inputs to one output. For example it could sit between two computers and a network switch. The TS3L301 looks promising, but I am unclear about the ...
0
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1answer
118 views

MAC PHY defenitions

from Wikipedia: The media-independent interface (MII) was originally defined as a standard interface used to connect a Fast Ethernet (i.e., 100 Mbit/s) media access control (MAC) block to a ...
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0answers
65 views

can i interface profinet protocol to ethernet interface?

i have a profinet device and an Ethernet port which is dedicated for KNX protocol. can i connect my profinet device to this Ethernet port?
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1answer
70 views

Ethernet PHY Layer Compatibility

I have two different embedded devices with ethernet connection. One is based on Texas Intruments DM648 DSP chip and the internals of the other are unknown to me. When I connect each one of them ...
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1answer
174 views

How often are bits sent over cat 5 ethernet cables?

sorry if this is a bit of a dumb question, but I read somewhere that cat-5 is 4 twisted pairs. so that means at most it's transmitting 4 bits at a time. What determines how often the 4 bits are ...
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2answers
60 views

Why use a custom module instead of a clock divider?

Background I have created a VHDL module that continuously generates a one-bit wide pattern of "1010101010..." as long as it's enable bit input is asserted high, as part of a class assignment. In the ...
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2answers
69 views

Why use a multiplexer the select from GND and VCC instead of an Inverter?

I have created a VHDL module that generates a one-bit wide pattern of "1010101010..." continuously, as long as an input signal called "start" is asserted high. This is the elaborated circuit design ...