Along with this Tech Note, is a link to the 'Enova DGX Input/Output Board and Endpoint Compatibility Instructions'. You should refer to that document for official firmware version reference. This tech note is for reference based on best practice and experience over time.
2.0.22 is the most stable version of firmware to run in DGX 8/16/32/64. DXLink TX should be at 1.6.69 and RX at 1.9.69. Hotfix version 1.9.73 is the same as 1.9.69 except that it has the necessary file to allow a brand new DXLink RX to run it (New DXLink RX endpoints couldn't be downgraded to pre 100 series firmware until 1.9.73). In other words, if your DXLink RX will not take the 1.9.69 firmware, it's a new RX and you should load 1.9.73. DXLink fiber TX should be at 1.2.12 and Fiber RX at 1.2.1. If everything is online and working correctly, you should not upgrade beyond these versions.
2.0.4 was created when DXLink endpoints started shipping with 100 series firmware. If a DXLink endpoint were being replaced in an old system, the new DXLink endpoint would likely have 100 series firmware loaded and will not come online. The DGX will not recognize the endpoint. The DGX would have to be updated to 2.0.4 for the DXLink to come online, so that you can load 1.6.69 and 1.9.69 firmware. It was not expected that you keep 100 series firmware in the endpoints. Although it may work, it was not tested and there could be compatibility issues, therefore is not supported. 2.0.4 also added a fix for a problem with an AIE board's audio disappearing, usually on the input extract side. Considering that you can downgrade DXLinks with the virtual master before connecting to the DGX, the only reason to upgrade to 2.0.4 is if you're having the AIE problem, or if you want to have the DGX ready for any potential 100 series DXLinks to be connected in the future. If you need to load 2.0.4, you should actually load 2.0.6.
2.0.6 is the same as 2.0.4 except for provision to recognize DXLink Input Boards with new flash memory parts and a fix for RXs going offline on system power up. If you plan to load 2.0.6, then please read 2.0.4 above.
2.2.7 and 2.2.8 should be upgraded to 2.2.12.
2.2.12 (along with its predecessors of 2.2.7 and 2.2.8) was created to allow the ability to use 100 series DXLink endpoint firmware and the newer 100 series DGX boards with the pre 100 series DGX. Unless you must upgrade to this version because of hardware, it is still recommended that you use 2.0.22 in the DGX.
