Optical decoupling of data acquisition devices from the readout system is mandatory in some applications (like installation on a platform under high voltage). In case of the SIS3316(-DT) 125MSPS 16-bit and 250 MSPS 14-bit digitizers optical decoupling can be established with readout over an optical Ethernet connection.
Starting with VME FPGA firmware revision V3316-200A Switch SW80-3 is used to activate/deactivate auto-negotiation for the Ethernet link. The switch has to be in on position for an optical connection and in off position for a copper connection or an optical connection over a media converter (like TP-LINK part number MC220L).
The tests were performed with a DELOCK PCI Express 1x SFP Slot Gigabit LAN card (DELOCK part number 89368), two SFP link media (TP-LINK part number TL-SM311LM or Finisar FTLF8524P2BNV, Struck part number 03145) and a standard LC-LC multimode duplex50/125 µm fiber.