Is Brain2 Spektrum Telem possible with just a SRXL2 Sat & no other RX
Can someone please clarify which, if any, current Spektrum Satellite receivers (eg SPM4651T) can be used, connected directly to the Brain2 sat port without any other receiver involved, can give telemetry (flight pack voltage at least) back to the TX, & what additional cables are required. ... or is a separate RX required.
My B2 is update to the very latest (August 4 2021) firmware release (3.4.xxx if I recall)
As you already pointed out, the Spektrum receiver to use to have for telemetry is the SPM4651T. Compared to the other SRXL2 receivers it is the best choice because it is the smallest, the lightest, the least bulky, the one that consumes less power but is full range.
SPM4651T is not a satellite but a real receiver; therefore, it should not be connected to the SAT1 / SAT2 satellite connectors but to the CH3 connector of the receiver.
On page 3 of the Wizard you have to select the SRXL2 protocol icon (don't get confused with the old Spektrum SRXL protocol icon, you have to select the multiprotocol icon with SRXL2 indicated).
Once the correct protocol icon is selected, the software will automatically select from the eighty plus schematics available the correct schematic to display in the next panel n°4 based on the type and model of controller connected to the software and the protocol selected.
The SPM4651T was one of the first receivers released two years ago with the new SRXL2 protocol and therefore as it was easy to assume, many firmware updates have been released to solve the many youthful problems of a completely new protocol.
It is therefore really important to update the firmware to the latest available version released this year to avoid all known and solved problems.
To do this you need to download the appropriate firmware and the USB dongle SPMA3065 with which you can also register the receiver on the My Spektrum website to get the warranty. It must be assumed that no receiver present on the shelves of stores can have the latest firmware released only a few months ago.
Regarding the connection and the possible redundancy, please refer to the FAQ section, Q 26 where we have already explained everything and we avoid to repeat it here.