Ethernet link & speed LEDs

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SeeCwriter
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Joined: Mon May 12, 2008 10:55 am

Ethernet link & speed LEDs

Post by SeeCwriter »

I'm using a NANO, and we built our own Ethernet 20ft test cable. Using the test cable we communicate fine over Ethernet, but the link & speed LEDs don't light up. If we use a normal store-bought Ethernet cable they do. I'm looking ideas on what to look for.
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TomNB
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Joined: Tue May 10, 2016 8:22 am

Re: Ethernet link & speed LEDs

Post by TomNB »

If you plug in your test cable between two pc's, do the led work?
SeeCwriter
Posts: 624
Joined: Mon May 12, 2008 10:55 am

Re: Ethernet link & speed LEDs

Post by SeeCwriter »

That would be a good test, but the configuration of the cable will not allow it. Because our product is an outdoor device, it has a waterproof circular cannon plug-type connector for the user interface. It contains RS-485, RS-232, and Ethernet. Our test cable splits off the signals for each interface to its own connector. There is clearly something about our cable that is different from other cables we've made. It's just odd that communication works but the LEDs don't. I'll keep working on it. Thanks.
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TomNB
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Re: Ethernet link & speed LEDs

Post by TomNB »

When you connect two ethernet devices together, there is a low level negotiation that takes place to determine speed and duplex. If that fails, then the default is typically 100M half duplex (but not always). So it could be that the negotiation fails completely, and the leds cannot represent a negotiation. You could check the speed/duplex on the netburner side. If not 100M full duplex, something likely failed.
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TomNB
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Re: Ethernet link & speed LEDs

Post by TomNB »

Meaning the wires have noise, coupling, etc.
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