NetBurner Community Forum

How can I detect a failed network connection quickly?

I have been using the EtherLink() function to check the link status on
a Mod-5272, but it seems to take several seconds to indicate a link failure after
unplugging the cable.

I would like to detect a failed link after 100 or 200 msec. Is there
anyway to do this?

Thanks,

Doug

This can be done by reading directly from the PHY registers. The release build Ethernet driver interacts with the PHY so we check for a link with EtherLink() at the software level. This ensures you will be able to communicate on Ethernet when gaining the link but can delay the indication of a lost link. The Debug Ethernet driver has no PHY interaction, so a call to the EtherLink() function returns the immediate link state reported by the PHY. Now that I think about it this EtherLink() function should change for release build so it checks both the PHY and software levels to ensure a link is valid. This way the software link delay is still present when gaining a link but there will be no delay from this function when indicating a link is lost.

You can find the EtherLink function code here:
C:\Nburn\"platform"\system\etherprint.cpp
or in your case C:\Nburn\MOD5272\system\etherprint.cpp

I changed the function to the following, this will be in future releases:

BOOL EtherLink()
{
#ifndef _DEBUG
if( !bEthLink ) // do we have link?
return FALSE;
#else
EtherInit();
#endif
if ( ( GetMII( PHY_addr, 0x01 ) & 0x0024 ) == 0x0024 )
return TRUE;
else
return FALSE;
}

After you make these changes rebuild the platform system directory and you should be good to go.

-Larry

Thanks Larry!
The updated Etherlink() function works exactly
like I need it to now.

Netburner support is awesome!

-Doug