Ethernet Basics

Why do you feel you have a need to control the LED:s?

That's like having a project to display some graphics on a monitor, and as step one ask how to control the power LED on the monitor.

Sir Per Westermark As a beginner first step ,that i need to control RJ45 LED's ..to know about that reason of led's usage practically ...and move further with confidence...

Perhaps a review of the schematic and supporting documentation might assist your comprehension.

Confidence gained through other people's knowledge/skill, not really that useful..

The manual for a cheap NIC you can install in your PC - or possibly a chapter in the motherboard manual - will tell you the reason for the LED:s and their practical usage. You'll get to see if there is a link. If there is traffic. And in some situations what link speed that has been negotiated. But controlling them will not really move your knowledge forward.

You are much better off trying to figure out what is a link. Or what negotiations that are normally performed when plugging in a cable. And even better off by worrying about what is TCP. And what is UDP and what is the underlying IP. And how does a device figure out where to send a packet. What type of addresses does exist and what different layers of the networking stack will care about different addresses. What happens if a packet is broken? What happens if a link somewhere is overloaded. How large packets can be sent, and what happens if you try to send larger packets than a link can accept.

There are so much things that are useful to know. Knowing how to turn on or off the LED:s on the connector is at priority -17 on a scale 0..100. The only really useful reason to be able to control them is if you want to intentionally lie to someone and present false information.

I have a feeling that in this specific case, the LEDs are of the least concern....

Thanks sir...