![]() Most devices support lower-speed modes, but not all. ![]() Is there also an issue with connecting a 4 wire device to a network that uses 8 wires? I think 10GBASE-T also uses echo cancellation techniques, but i'm not positive on that. On older hardware, you had to manually ensure that transmitter was connected to receiver (using crossover cables if needed), but more recent hardware usually has AUTO-MDIX which figures it out automatically.ġ000BASE-T uses all four pairs in both directions at the same time, using echo cancellation techniques to separate received data from transmitted data. 10BASE-T and 100BASE-TX used one pair in each direction. Is it that all differential pairs (DA: pins 1 & 2, DB: pins 3 & 6, DC: pins 4 & 5, DD: pins 8 & 7) are busses where data can be transmitted both ways (unlike the UART where RX has to be connected to TX)? and in case I am just using 2 pairs, would I be connecting only DA and DB? I am unsure about how data is transmitted over Ethernet. Transformer coupling does have some downsides transformers don't work on DC, and small transformers that work well at high frequencies don't work well at low frequencies but this is easily dealt with through line coding schemes that avoid low frequencies. Thirdly, it is easier to design transformers for high frequency (aka high speed) than optocouplers. Secondly, transformers are very good at generating and receiving differential signals while providing high common mode rejection this makes them a good combination with twisted-pair wiring. Firstly, the signal power passes through the transformer, which means you don't need to get a power supply to the "isolated" side of the barrier. Transformer isolation has a couple of major advantages. There are basically two options for isolation, opto and transformer. You don't want fault current/voltages in from faults in the mains wiring or devices to spread through your communications wiring. Isolation is a very good idea in communications systems that are linking lots of hardware over a wide area. For this reason the device-side of the transformers is usually center-tapped. Typically they are also used as part of the signal conditioning, turning a pair of single-ended drives into a differential signal on transmit and establishing the correct common mode voltage for the receiver on receive. They are always used, not just when "sent over a lengthy cable". I have been told that Ethernet magnetic transformers are used for base-t Ethernet when transmission is sent over a lengthy cable. Is it that all differential pairs (DA: pins 1 & 2, DB: pins 3 & 6, DC: pins 4 & 5, DD: pins 8 & 7) are busses where data can be transmitted both ways (unlike the UART where RX has to be connected to TX)? and in case I am just using 2 pairs, would I be connecting only DA and DB? Is there also an issue with connecting a 4 wire device to a network that uses 8 wires? I'm sorry if I may not be coherent in my question as I am not too familiar with Ethernet hardware. Would the same circuit work for a 4 wire (100base-t) configuration if I connected only pins 1, 2, 3 & 6? if so would the performance be the same as the 8 wire configuration? What is the purpose of the transformer? (is it for signal filtering or boosting?)Īdditionally, I have a circuit that has been used for an 8 wire (1000base-t) Ethernet configuration. ![]()
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