0 Replies Latest reply on Nov 6, 2012 3:22 PM by yiwang

    82579LM - LEDs work in a strange way

    yiwang

      I am trying to connect one PC and one embedded device directly with a crossover cable and make a data transmission between them. There is general connection info as below:

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      PC:

      OS – Windows 7

      Network Adapter – Intel 82579LM; driver version – 12.2.45.0

      Send and receive packet using Winpcap library

      Device:

      No OS

      Network Adapter – SMSC LAN91C111

      Send and receive packet directly using Ethernet chip driver interface

      Transmitted packet uses my own protocol on data link layer which is not related to any network Ethernet protocol such as arp, tcp/ip.

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      My problem is when setting device to auto-negotiation and PC to auto-negotiation or 100 full duplex and plugging crossover cable, I can see two LED indicators on both side blinking together at the same time about once a second. It does make sense because one of LEDs should be solid green for Ethernet link established. After that, PC becomes slow and “display driver stopped responding” message shows up.

      But I do the same thing to connect the PC in Windows XP and device, everything is fine. PC can detect stably of the network link with device and data transmissions are stable with the following network setting: PC – 100 full duplex; device – auto-negotiation.

      And I also make an experiment in Ubuntu. It turns out that under the same situation, PC still can detect the link from device. If I use straight cable with switch to connect them (all OSs), there is no problem at all.

      I just can’t seem to figure it out. Anyone have any suggestions? Thanks in advance.