Skip to main content

Questions tagged [ethernet]

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.

Filter by
Sorted by
Tagged with
0 votes
1 answer
35 views

Jumper on 100 Mbps Ethernet

Is it possible to pass a 100BASE-TX signal (100 Mbps Ethernet, over 2 differential pairs) through jumpers (one per wire), in order to allow the user to select Ethernet or serial for a given connector? ...
Sandro's user avatar
  • 7,697
0 votes
1 answer
37 views

10/100 Ethernet PHY: What is this capacitor for?

10/100 Ethernet PHYs such as ENC28J60 and DM9051 recommend the following external components on each pair. What is the circled capacitor for? Any balancing that it provides would seem to be ...
personal_cloud's user avatar
0 votes
0 answers
46 views

Why does the SPI bus with 2 devices crash in this setup?

I am using Feather M4 express development board with DC Motor + Stepper FeatherWing and Ethernet FeatherWing stacked on it. The idea is to control the steps of the stepper motor by reading the encoder ...
dreamcoder's user avatar
1 vote
1 answer
26 views

MII to SGMII to connect ETH Switch is it possible?

I want to connect MCU with parallel MII interfaces to switch ICs with SGMII interfaces in this method : The Eth SW support 8xMDI Channel and 4xSERDES(SGMII,USXGMII,5GBASE-X , ETC). I'm afraid that I ...
Knowledge's user avatar
  • 441
-1 votes
0 answers
47 views

Make CAN-bus connection as netif interface (LWIP) [closed]

I want make network connection between 2 STM32F407 by CAN-bus protocol (without use physical Ethernet RMII/MII). Could you help me how can i do this? I think I have make CAN connection as netif (...
MohammadRasoul Ilali's user avatar
0 votes
0 answers
20 views

CPU to Switch SGMII port with PCIE 2.5Gb

I can't seem to find a 2.5 Gbps Ethernet controller that could be a bridge between the SGMII+ port and PCIe. this is what I want to do: I don't want to use PHY (from the copper 2.5G to 2.5G SGMII) ...
Knowledge's user avatar
  • 441
9 votes
2 answers
816 views

Is there a way to non-destructively test whether an Ethernet cable is pure copper or copper-clad aluminum (CCA)?

I got an Ethernet cable on Amazon for what was, in hindsight, a suspiciously good price. The description says it's copper but one of the one-star reviews claims it's actually copper-clad aluminum (CCA)...
hbraunDSP's user avatar
1 vote
0 answers
30 views

Why does the SJA1105QELY Ethernet Switch chip stop sending packets after it has sent 48,790 bytes

Why does the SJA1105QELY Ethernet Switch chip stop sending packets after it has sent 48,790 bytes? I designed a circuit card containing the SJA1105 Ethernet Switch made by NXP. After doing a reset and ...
user4574's user avatar
  • 12.4k
4 votes
1 answer
308 views

Can a capacitor be used to close path between center-tap and shield instead of Bob-Smith (capacitor+resistor)?

I believe this has already been quite a controversial topic, but I'm wondering if just a capacitor can be used to direct the common-mode (CM) noise away from the center-taps (CT) of a CM choke back to ...
Rockker's user avatar
  • 83
4 votes
2 answers
663 views

1000Base-T vs. 100Base-TX captured waveforms and link performance

I have a Gigabit Ethernet port and currently I try to troubleshoot an asymmetry in data throughput. Doing iperf3 testing I notice that sending is at 900 MBit/s and receiving at 400 MBit/s. During that ...
stowoda's user avatar
  • 582
0 votes
1 answer
97 views

Why are common mode chokes used in Ethernet magnetics

I’m trying to understand the reason the common mode choke is required in Ethernet magnetics. To understand, if we look at the schematic, with the common mode choke (horizontal coils) removed, we are ...
EricEverton's user avatar
0 votes
2 answers
99 views

High speed data transfer from STM32 to the PC

What is the best way to transfer high-speed data (12.288 Mbit/s) from the STM32H723 microcontroller to a PC? I'm controlling a four-channel audio codec (AK4619vn) and need to sample the FFT of the ...
Yusuf Dolu's user avatar
7 votes
3 answers
260 views

ESD knocking out PHY on device with unisolated POE

I inherited this design, one problem I am having is ESD on the chassis knocks out the PHY, sometimes it can't even be reset via software. I am curious if anyone can spot any glaring errors with the ...
Voltage Spike's user avatar
  • 84.7k
1 vote
1 answer
48 views

Connecting two W5500 via UDP results in PHY link off

I want to connect two STM32F4 and to communicate via UDP. At the moment I only want to send data from one to another mcu. I have tested tx and rx communication separately with PC - python scripts and ...
macola995's user avatar
  • 109
1 vote
0 answers
117 views

Ethernet signal from STM32H7 to LAN8742A good, link good, receive good, no transmit

I am working with a custom board based on the NUCLEO STM32H745. The STM32H745 will receive a broadcast ping and ARP. It will try to respond to the ARP and disregard the broadcast ping. I can trace the ...
andy__H's user avatar
  • 11
0 votes
1 answer
42 views

What kind of IC is this - damaged in the TQFN10 housing, marking WEA

I have a problem with HMI Allen Bradley, The ETHERNET port does not work, I found out that this area is powered by an IC in the TQFN10 housing with the code WEA. What kind of arrangement is this?
wojtiqs's user avatar
0 votes
1 answer
61 views

Synchronizing multiple ECUs

Say I have an ECU that controls the exterior LED lighting of a building, for aesthetic purposes. Due to the size of the building and the amount of LED strips needed, multiple ECUs are needed, each ...
HV16's user avatar
  • 345
0 votes
1 answer
37 views

EFT on powersupply AC input

My system I use 110 V to 36 V power brick (medical grade), and having hybrid cable which takes this 36 V and Ethernet and goes to the system. I am testing the EFT as per 61000-4-4 (± 2 kV, 100 kHz ...
NICEGUY NICEGUY's user avatar
7 votes
6 answers
5k views

Ethernet port as a signal generator

I was wondering if it's possible to turn a PC into a signal generator through the ethernet port (or at least an amplitude-modulated sine generator). I specifically care about the ethernet port since ...
KKZiomek's user avatar
  • 141
1 vote
1 answer
93 views

Should the RX and TX lines have the same length for an Ethernet PHY? [duplicate]

I have the ethernet PHY Realtek RTL8211F-CG and I wonder if the RX and TX lines should have the same length? In my case, I have placed the TX and RX lines like ...
euraad's user avatar
  • 1,324
1 vote
1 answer
119 views

How can I configure RealTek RTL8211F for 100Base-T?

Introduction I'm planning to use RealTek RTL8211F Ethernet PHY. I have an example schematic. Problem The problem here is that the RJ45 Ethernet connector 48F-01GYDXNL is very difficult to get and I'm ...
euraad's user avatar
  • 1,324
1 vote
1 answer
60 views

Ethernet cable testing

I'm working on designing a device to identify ethernet cables after they have been installed. I've designed a circuit that will send a DC high signal via one wire and then returned over the remaining ...
Paul B's user avatar
  • 11
0 votes
1 answer
92 views

RTL8153 without EEPROM

I am making a usb hub board with built-in ethernet to USB feature with RTL8153. Similar to the following post I found the datasheet does not say anything regarding how to program the eeprom or if it ...
Chanoh Park's user avatar
2 votes
1 answer
255 views

1Gbps Ethernet : use shield for slow signal?

Short version : Is it OK to use the shield of an Ethernet cable to carry a very slow analog signal (100Hz bandwidth is great, 1Hz is OK)? Nb : I don't care if I get some >1MHz noise on my analog ...
Sandro's user avatar
  • 7,697
0 votes
0 answers
26 views

Communication between Microblaze and RTL IP core

I have done an ethernet project (Echo) (TCP/IP) using vivado block design and the board used is Artix A7 and MICROBLAZE PROCESSOR WITH AXI_INTERCONNECT. I was able to use AXI_GPIO connected to an led, ...
Yosh Sinjab 's user avatar
0 votes
2 answers
67 views

Which of these 2 phenomena occur first - AN or MDIX

Most of these days, the Ethernet PHY/switch devices support Auto-MDIX and Autonegotiation. So, when a link partner is getting connected to a PHY or a Switch, which of these two phenomenons happens ...
Novice's user avatar
  • 1
0 votes
0 answers
36 views

Can't find ethernet packets sent by TMS570LS1227 microcontroller

SOLVED: there was a setting in HALCoGen that enabled loopback mode. I am stupid. I am attempting to send a small packet over the ethernet port on a TMS570LS1227 using a TI-provided function I'll show ...
hobbes274's user avatar
0 votes
0 answers
33 views

Parametric or Template test by Ethernet Compliance Test

I am trying to design this part of TC6 from Ethernet test fixture board. As I dont need rest part of the parts for my test. Can someone tell me what are the loads are? Here three different loads can ...
Alok's user avatar
  • 1
0 votes
1 answer
115 views

Wiznet W5100 and Realtek RTL8363NB-VB-CG board issue

I've built a PCB connecting one of the ports of the RTL8363NB-VB-CG to the W5100 mimicking a ethernet cable on board, I used a RP2040 a Wiznet 5100S-L and the Realtek RTL8363NB-VB-CG.The problem that ...
TFO's user avatar
  • 3
0 votes
0 answers
38 views

ENC28J60 heating issues

Here, I add the schematic and PCB layout of ENC28J60 module. It's working properly, but it's getting too hot. It's around 103 Degree Fahrenheit. How can I minimize this heating issues?
Ruman's user avatar
  • 1
2 votes
1 answer
88 views

Why do my boards shut off when I connect an RJ45 cable to a switch but not a router?

I made a custom single board computer based on the Allwinner V3s. This system on chip has an integrated PHY. All components seems to work except I noticed that when I plug the ethernet cable to a ...
Varech's user avatar
  • 305
1 vote
1 answer
95 views

Why didn't 10GBASE-T Ethernet replace 1000BASE-T? [closed]

1000BASE-T (gigabit Ethernet over copper twisted pair) seems to have largely replaced 100BASE-T (100-megabit Ethernet over the same medium) in new equipment. However, 10GBASE-T (10-gigabit Ethernet ...
Shivaram Lingamneni's user avatar
0 votes
0 answers
11 views

Ebyte NS1 Design question

I am working on a new design dev board base on stm32h750 and Ebyte NS1 Ethernet Module . Ebyte give 2 design in data sheet . 1 one with a filter HR641680E 2 with a RJ45 build in 2KV electromagnetic ...
Khales Naim's user avatar
0 votes
1 answer
108 views

Ethernet with incorrect pinout still makes link?

I designed a board recently that accidentally had an incorrect pinout on the RJ45 jack for Ethernet. Instead of following TIA568, I instead routed it straight-through: Oh well, simple mistake, ...
Reid's user avatar
  • 145
0 votes
0 answers
32 views

3 bit to 2 trit mapping scheme derivation

3 bit data can be converted to 2 bit trit to increase the bandwidth efficiency. I don't know how did one come up with such mapping technique. Is there any derivation for this? Will this mapping scheme ...
Isha's user avatar
  • 1
-1 votes
1 answer
60 views

Self clock synchronization in NRZ-I encoding

I was going through NRZ-I encoding technique, somebody mentioned that long stream of 0's will cause loss of synchronization in NRZ-I encoding scheme. But how? What I understand is the receiver should ...
Isha's user avatar
  • 1
0 votes
2 answers
56 views

Clock synchronization in ethernet PHY

I am beginning to start with ethernet PHY. As per my understanding, digital signal will be transmitted and we apply encoding scheme to incorporate clock information into the data signal. Can't we just ...
Isha's user avatar
  • 1
1 vote
0 answers
67 views

LAN8720 MDC (SMI Clock) and/or ringing issue

I had always difficult times with designs having LAN8720 device on it. It behaves differently with each design (this is understandable and even I carefully design it according to the design ...
Sener's user avatar
  • 273
0 votes
1 answer
76 views

Harmonics of Ethernet (100MBps) MLT-3 signals [closed]

I have EMC Issue (Radiation) as attached..where at some frequencies the emission levels are exceeding the limits.. I use 36V power and Ethernet (MLT3) for communication. These failing frequencies are ...
NICEGUY NICEGUY's user avatar
3 votes
1 answer
199 views

Ethernet controller EMC failure

I designed my very first Fast Ethernet PCB and it is having a hard time passing Radiated Emissions. The result came back from the test lab shows that it is radiating strongly at 125 MHz: In the ...
HV16's user avatar
  • 345
0 votes
1 answer
131 views

Ethernet PHY design query: Compatibility of DP83848QSQ/NOPB with STM32F407VET6 and pin configuration concerns

I'm relatively new to Ethernet PHY design and currently working on a project where I've chosen the DP83848QSQ/NOPB PHY and plan to connect it to the STM32F407VET6 microcontroller. However, I've ...
user avatar
0 votes
0 answers
71 views

Are 10GBASE-T ethernet magnetics modules compatible with 1000BASE-T?

I am designing a board with a 1000BASE-T ethernet PHY and I want to use a discrete magnetics module since I will be using a non-standard connector. However, I am constrained with space and I found a ...
Matias B's user avatar
0 votes
0 answers
70 views

Help troubleshooting a PoE circuit

After much ado I've designed a simple PoE addon board for a custom ESP32. However, when plugged in, the PoE light on the switch goes on for about half a second, and then goes back off. Seems like its ...
Maciej Swic's user avatar
1 vote
2 answers
199 views

Ethernet MAC Controller IC design process

I'm from an embedded software background, and I am trying to learn more about chip design. To this end I want to understand what goes into designing and implementing a digital IC like an ethernet ...
NeedToKnow's user avatar
1 vote
1 answer
85 views

Can I run PoE++ on DisplayPort/HDMI over Cat6?

I'm working on a project for an industrial application where I need to run a monitor with a single cable carrying both data and power. 7" LCD with a few Watts backlight, 1024x600@30fps or so, ...
Mitcham Tuell's user avatar
0 votes
1 answer
58 views

Power limitations for Ethernet cabling

I have a 60 watt constant current Meanwell driver that has the following output options: .9 amps @ 67 volts or 57 volts @ 1.05 amps. I want to know what specific ethernet cable is required. Can I ...
Tim's user avatar
  • 9
0 votes
1 answer
172 views

Vivado Ethernet IP core licensing issue

I have a PL design in which I included a 10G/25G Ethernet Subsystem IP core from Xilinx configured with BASE-KR, AN/LT logic and FEC logic for Clause 74. When I try to generate the bitstream, I am ...
Roy Meijer's user avatar
0 votes
2 answers
158 views

Can I use thicker wires or twisted pair for Ethernet?

I'm planning to use 2 types of connectors: A : GND + 24V + 100Mbps ethernet (4 wires) + 2 wires with various functions B : 1 Gbps ethernet with PoE (8 wires) For type B, I found of the shelf ...
Sandro's user avatar
  • 7,697
0 votes
1 answer
110 views

Is there concept called dual ethernet? [closed]

I came across a word called dual ethernet while working on a project and it got me curious like is the word misspelled or is there any real concept on this?
Subzee's user avatar
  • 21
0 votes
1 answer
98 views

With what can I replace a MLCC capacitor to ground of 6.3V and 4.7uf

I have a mobo and the cap highlighted above in the picture C4 (6,3V 4,7uF) has broken off, I want to know what can I replace it with if I dont have specifically the same voltage and capacitance but ...
theo1996's user avatar

1
2 3 4 5
25