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.

0
votes
0answers
37 views

problem connecting an Arduino Ethernet Shield to FPGA trough SPI

I have an Arduino Ethernet Shield and trying to connect it to my spartan 6 board. I used the ICSP header on the bottom of Arduino Ethernet Shield (MISO/SCK/RST/+5/MOSI/GND) and a wire for SS(pin 10 of ...
0
votes
1answer
60 views

Ethernet magnetics [duplicate]

I am working on a system prototype which includes two ethernet switches (KSZ9896) to provide Ethernet Gigabit connectivity between several devices (let's call them slaves, from now on); every slave ...
1
vote
1answer
112 views

How to get ip address Schneider PLC controller TM218LDAE40DRPHN? [closed]

I am new to PLC technology and I am doing the following step, listed below: Connect from PLC to retrieve data through Ethernet using Modbus TCP/IP. I found that PLC didn't have its IP address ...
0
votes
1answer
86 views

Does disconnecting the Tx+ and Tx- wires in the ethernet cable make it Unidirectional for Packet (TCP) sniffing

The DCSW-1005(10/100Base-T) Ethernet switch/TAP can be used as a network TAP (as well as Ethernet switch), in which a copy of outgoing and incoming packets associated with Port 1 (Target port) are ...
0
votes
3answers
252 views

How to route Ethernet PCB ? [closed]

I am new to PCB routing. In one of my projects, I need to be able to exchange data between nano-computers (https://www.variscite.com/wp-content/uploads/2018/01/DART-6UL_DART-6UL-5G_Datasheet.pdf) ...
1
vote
2answers
87 views

Divide RS-485 Simply without switch

I have an RS-485 input / output from a solar charge controller (SCC) and would like to read the output in two locations, while maintaining its input from one, or hopefully both of those locations (see ...
1
vote
2answers
163 views

TVS diodes for Ethernet/PoE?

I am getting confused in selecting TVS diode for Ethernet Interface. Should I connect one bidirectional TVS diode across a ...
2
votes
1answer
172 views

Using capacitors for ethernet isolation? [duplicate]

The standard for ethernet says you should use a transformer for isolation. It seems like a cap-based solution would be smaller, more versatile, and a better fit for my application. Is there any ...
0
votes
0answers
32 views

CC2530: adapting AVR/pgmspace.h for Zigbee

Goal: Adapt ENC28J60 codes written for ATMega328p (http://tuxgraphics.org/electronics/201204/embedded-ethernet-client.shtml) for CC2530. Problem: No equivalent library for AVR/pgmspace.h available ...
0
votes
1answer
47 views

Connection of LAN8742A nRST pin causes failure when ESD strike

My circuit uses LAN8742A ethernet phy. The system has a metal case and gets 220V AC to power supply board. After converting 5V DC it goes to my board that has Ethernet and mcu. I screwed case and ...
1
vote
1answer
191 views

ESD strike breaks the LAN8742A ethernet phy

My circuit uses LAN8742A ethernet phy. The system has a metal case and gets 220V AC to power supply board. After converting 5V DC it goes to my board that has Ethernet and mcu. I screwed case and ...
0
votes
1answer
33 views

Interrupt during packet transfer

I'm using the mbed TCP/IP Socket library to receive incoming messages via ethernet. Currently, the incoming data is read in an infinite while(1) loop (i.e. as fast as possible). I will also be ...
5
votes
2answers
416 views

DP83848 + STM32 & Failed EMC (massive spikes of 25MHz crystal harmonics)

So we've failed EMC two times now because of spikes of 25 MHz harmonics from 175 MHz to 300 MHz, especially 175 MHz, 225 MHz and 275 MHz with peaks easily 30-40 dBuV above noise floor measured with ...
2
votes
2answers
78 views

Finding an Ethernet transformer when I have it's characteristics

I am using the Novatel OEM729 board for a project, and I need to implement Ethernet in the project. According to the Novatel OEM7 manual, page 48, the OEM729 does not have Ethernet magnetics, so I ...
1
vote
2answers
123 views

How does Ethernet to CAN conversion work?

I am wondering how an Ethernet-to-CAN converter works. CAN is a multi-master broadcasting network where messages are associated with IDs. Each message type has a unique ID. Devices listen to all ...
1
vote
0answers
30 views

ENC28J60 rejects unicast packets - unicast filter is on, MAC is set, and addresses match

I'm programming an ENC28J60 driver at the moment, and have encountered something odd when attempting to receive packets. More specifically, unicast packets. According to the datasheet, when the ...
2
votes
1answer
65 views

Power over ethernet and common-mode termination

I have a non-standard Power over Ethernet application (connector, and devices are not ethernet standard but we are using ethernet pairs and protocol for communications). On looking at PoE schematics I ...
0
votes
1answer
129 views

Proper connection of choke coil in ethernet magnetics

I need to use the medical ethernet magnetics by Pulse HXU6200NL (it is the only 2MOPP medical-certified PoE magnetics I can find). These are of the rather common transformer/choke coil topology. My ...
1
vote
2answers
124 views

Double ethernet magnetics for a passive medical application

I am designing medical data acquisition equipment that requires moderately fast data transfer. As part of the design we are using a custom 100BASE-T PoE architecture (and cabling) to the data ...
0
votes
1answer
108 views

How come this non-standard ethernet wiring works?

I am setting up ethernet in a friends house with cat 5 cabling. I do not do this professionally but I have made like 20 patch cables and installed about 20 wall sockets before in my own house. My ...
1
vote
1answer
52 views

Designing an PCIe ethernet NIC with built in ethernet switch

I am trying to design a ethernet network card that will plug into a PCIe slot and have 2 etherenet ports visible to the user that are connected by a unmanaged layer 2 switch. My architecture ...
5
votes
4answers
2k views

CAT5 for telephony

I wish to extend my incoming telephone connection using CAT5 as I've heard it could provide better performance than standard single stranded telephone wire over long distances. There are only two ...
2
votes
1answer
115 views

Ethernet controller not recognized on PCIe bus

I designed a carrier board for this SOM: https://wiki.solid-run.com/doku.php?id=products:ibx:documents As I need a second Ethernet port I added an Intel I217 Ethernet controller. Unfortunately it ...
1
vote
1answer
132 views

Cable Side and Physical Side of a PoE Magnetics

I am reading the datasheet of PoE Magnetics. I am not able to understand which side belongs to cable side and which belongs to ...
0
votes
2answers
280 views

Ethernet switch with 8 ports and PTP [closed]

Hello) I need a solution for a board with 8 100/10 ethernet ports (with copper/fiber switching capabilities, PTP and idealy also with PRP, HSR protocol capabilities). I've found KSZ8999I switch, but I ...
0
votes
1answer
71 views

Should I model an ethernet message decoder with byte based instead of bit?

The steaming interface (for example the Avalon ST) input logic data[255:0] in_data; // a 256 bits input stream data The local signals of data like this: ...
1
vote
2answers
490 views

Using SFP modules from a microcontroller

I'm interested in having an embedded device send data optically. This is for test and measurement, where having conductive cables is problematic since it will perturb the measurement. The device is ...
2
votes
1answer
698 views

How can I configure PHY in cubeMX on own board?

I made a customboard using STM32f217VET microcontroller and KSZ8081 PHY (builtin pull-up resistors for TXP TXM and RXP RXM). I Configured my board to use MII mode, anda I used a 25MHz oscillator to do ...
1
vote
2answers
517 views

Impedance Matching Resistors on MII Ethernet Lines

Microchip is taking forever to activate my account so I will ask this here... I am using the KSZ8081 PHY for MII Ethernet. https://www.mouser.com/ProductDetail/Microchip-Technology-Micrel/...
6
votes
2answers
135 views

Can 64b/66b be forced out of DC balance by malicious data?

Unlike 8b/10b and 64b/67b, 64b/66b relies entirely on the scrambler for ensuring DC balance. This raises the question: can a malicious data stream force the line to leave DC balance? Or would it ...
1
vote
4answers
171 views

Fiber-optic transceiver ICs for applications other than fiber-optic Ethernet? [closed]

When we talk about fiber-optic transmission, we almost always talk about copper to fiber-optic Ethernet conversion using fiber-optic transceivers. But since fiber-optic communication is just ...
0
votes
0answers
70 views

Testing Ethernet cable with a signal generator and scope

I have been having some problems with my Ethernet lately and would like to test the cable. I was thinking I could borrow a signal generator and oscilloscope from work and get them hooked up to the ...
0
votes
1answer
123 views

1000BASE-T MDI Return Loss Measurement

IEEE 802.3's clause 40.8.3.1 specifies a certain a MDI return loss. The specification states that this return loss shall be maintained at all times when the PHY is transmitting data or control symbols....
1
vote
1answer
83 views

PHY Register 5 Technology Ability Field Meaning

I have a question about each bit fields(bit 5 to bit 8) of PHY register 5. The following is the description page of a PHY. I know that these fields are Technology Ability Field which is the link-...
0
votes
2answers
106 views

Inverting REFCLOCK of Ethernet PHY

A few years ago I had to design a board that uses the NXP LPC1769 MCU and had Ethernet connectivity. I was in need of a PHY chip and the LAN8720 was choosen. During design however, I noticed that NXP ...
1
vote
1answer
141 views

LAN9500A Ethernet Adapter

I'm designing a USB-to-Ethernet adapter (actually a prototype of a piece of a larger board). As those following my questions will know, I've had some ups and downs getting the USB part working, but ...
0
votes
2answers
114 views

LVDS Flex Cables - Optimizing Trace Layout for 10 GbE

I want to run a 10 Gigabit Ethernet (GbE) signal over a 15 pin LVDS flex cable like this one: My PCB will accept an RJ45 connector, and those traces will run over the PCB to the flex jumper, then ...
4
votes
1answer
391 views

KiCad Bus on multiple sheets - Are labels the right way to go?

I want to connect bus-lines via several-sheets in KiCAD 5.0 But I don't know whether I got that right. Please consider the following design: Shown in Figure 1 you can see my connection from the chips ...
3
votes
2answers
498 views

Ethernet ground multilayer pcb

I'm currently re-designing a 12-layer pcb. The only thing I am still struggling with is the routing of the ethernet. The layer stackup is as follows: Top Layer GND_1 MidLayer_1 PWR_1 MidLayer_2 ...
7
votes
1answer
206 views

Are Ethernet (copper 10/100/1000) compliance tests mandatory?

The IEEE 802.3, for Gigabit Ethernet, and supposedly the ANSI INCITS 263*, for the Regular and Fast Ethernet, have lists of signal quality requirements, which are generally tested using the so-called ...
0
votes
2answers
312 views

How reliable is using couplers to extend Ethernet cables?

I want to obtain one 90 meters of Ethernet CAT6 cable(with RJ45 connectors) by using three 30 meters of CAT6 cables with RJ45 connectors. The only option I could find is to use three such couplers. ...
2
votes
4answers
151 views

Analog Audio Signal over dedicated Ethernet/Twisted Pair Cable

I need to send an audio signal over 3 meters and back again on the same line (the plan is to put an on/off switch and a volume regulator at the end of the line). Additionally I would like to send 12 ...
1
vote
0answers
103 views

Servo sometimes freezes when used with another servo and MFRC522 RFID reader

I have looked, Googled and researched all over by now and I have not been able to find anyone experiencing a similar issue to mine, so I thought now would be the time to ask my own question on SE. ...
1
vote
2answers
60 views

Fitting USB Data in Cat5 Cable with External Power

I have a camera system at home with a DVR, which connects to a VGA monitor and mouse with which you can read and edit its settings (the cameras can be accessed over the Internet). I've been trying to ...
0
votes
2answers
102 views

Ethernet transformer saturation at low frequencies

I am using a 10/100BASE-T Ethernet transformer TG110-E050N5RL (Circuit A in the datasheet) in a circuit. I am applying a 60 Hz 500 Vac hipot across C9 (T1 pin 16 and T1 chassis ground) as shown here: ....
4
votes
1answer
328 views

Should I terminate the MII/RMII interfaces?

For Ethernet PHY design, the MDI interface should be terminated. Then how about the MII/RMII or GMII/RGMII interfaces? I've seen some designs terminated them, and most not. There are some PHY chips ...
-1
votes
1answer
171 views

Internet Radio Device with batteries [closed]

I have an project that I will make connection with Internet and listen a stream(in my case IP:port online radio station) then decode the music and transmit it to speakers connected to the ...
2
votes
2answers
303 views

Use crystal or oscillator for a Ethernet PHY?

I've saw so many reference designs use just a crystal to generate the clock for ethernet phys, though they can be generated with a crystal oscillator too. Such as KSZ9021's 'XI' and 'XO' pin. Are ...
0
votes
2answers
209 views

How does “bidirectional” transmission on gigabit ethernet work 2?

I was looking for an answer to the question how the 1000BASE-T transmission works and I came up with this post How does "bidirectional" transmission on gigabit ethernet work? but still a few ...
2
votes
1answer
294 views

Embedded Ethernet Solution w/ PoE+; SPI or MII?

I am currently undertaking my first hardware design attempt of an embedded Ethernet project w/ PoE+. I have experience working with embedded systems with Ethernet (mostly ARM M3/M4 processors with ...