SFP disable line on TEBA0841 base board

[WallyG]

Hi,

I've plugged a FPGA (TE0741) into a TEBA0841-01 base-board. Everything works fine...except I have trouble with the SFP+.

When I plug a (passive) copper cable into SFP+ connector everything works (I can get a nice 3Gb/s link through the copper loopback cable using the FPGA TX/RX transceivers)

When I plug an (active) optical cable into the SFP+ port the link is totally lost.  I tried several optical cable with the same result.

My best guess is maybe I need to pay attention to the SFP+ "TX DISABLE" signal.   (It should be 'low' to power the SFP+; but by default it is has a weak pull-up inside the connector according to the SFP+ standard).

The schematics for the TEBA0841-01 shows the TX DISABLE entering the SFP+ connector, but I cannot find this signal elsewhere in the schematic (schematic : https://www.trenz-electronic.de/fileadmin/docs/Trenz_Electronic/carrier_boards/TEBA0841/REV01/Documents/SCH-TEBA0841-01.PDF )

How can I make sure TX DISABLE is low on the TEBA0841-01 ?

Or maybe someone has another theory why my copper link works but an optical fibre link doesn't?

thanks for any help

Wally

[Antti Lukats]

Hi

will be fixed in next PCB version. We managed to connect all not-important side-band signals, and the ones that are important are dangling. This can be "patched" with some small piece of solder as there are VIA at those signals. We will contact you on email too to find solution for you.