Connecting MS510TXPP to XS505M via AXM761 SFP+

Hi,

I've got a MS510TXPP and I'm trying to connect it to an XS505M via two AXM761 SFP+ modules.

I've got an existing fiber cable ran between two locations.  The cable I've got running between the two is OM2 50/125 Duplex w/ SC connectors and it's 425FT long.  I'm currently using a TRENDnet TFC-110MSC to connect between the two points but I've reached link capacity and am having trouble with dropped packets.  I believe the fiber cable to be good because the link on the TRENDnet works.

With the two Netgear switches on either end, I plug in the AXM761 SFP+ modules and can see the light on the Tx side so I believe the modules are both working.  I'm using an SC/LC adapter cable on either end.  I can still see the light with the adapter connected.  When I connect them I get nothing, no LED's on either switch.  My guess is the 'polarity' should be Tx on one side to Rx on the other.  I've tried it both ways and still get nothing.  I can go back to the TRENDnet and it connects and works fine.

Any suggestions on how to troubleshoot?  I'm stumped.