Meaning of XDAB connector leds

The front panel XDAB LEDs are as simple as you would expect. Here is the code:

Solid Green: All is good.
Blinking Green: The system is functioning with one link missing.
Anything Red: There is more than one failure, the system will not function. These errors must be cleared.

If you are suspecting that the XDAB cable or XDAB ports on your NION are not healthy, it is easy to do an External Loopback Test to verify functionality.

To do an External Loopback Test on the XDAB, the role in that NION must be either stopped or erased. Then, connect a known good XDAB cable between the XDAB IN and XDAB OUT ports on the NION. Finally, on the "Hardware" page of the NION's web interface, run the External XDAB test each direction, both clockwise and counter-clockwise. You should experience no errors. If you do experience errors, substitute a known good XDAB cable. I would expect a cable failure before I would expect an XDAB interface to fail.

Another important note, be sure that the total cable length of your XDAB loop does not exceed approximately 40 feet. You need to add the length of all of the XDAB cables. This points out the issues with using several long cables to build your XDAB loop. You should use cables that are as short as practical. The 24" cables that ship with NIONs today are a good compromise between length and performance and should allow many NIONs to be assembled in a single XDAB stack.

Remember, an XDAB loop should ONLY include the NIONs in one project, and only the NIONs that are needed in that project. To make all the NIONs in a stack needed, hard assigning a meter device to each NION and feeding that meter some signal from the XDAB may be necessary, if you have not yet finished all your work.