Is it possible to update firmware if Tx and Rx have different firmware?
Yes, you will need to disconnect TX from RX and upgrade or downgrade the Rx first. After Rx is on the same firmware with Tx, you can connect them together to proceed next upgrade.
Does XD641 support 3840 x 2160 (UHD) 50P and 50i?
None of our products supports 'interlaced video', so 50i will not be supported. However, 50hz Progressive on the XD641 will.
Does XD641 support DP++?
None of our XD600 range is DP++ compatible.