Interesting details/analysis by a control guru which **may** help explanation of which sensor does what and how
https://www.satcom.guru/2018/11/737-...n-command.html
Obviously put together after LionAir . .
Peter was Boeing avionics supervisor for 767 and 747-400 data link recording, data link reporting, and satellite communications. He was an FAA designated engineering representative (DER) for ACARS, satellite communications, DFDAU, DFDR, ACMS and printers. Peter was lead engineer for Thrust Management System (757, 767, 747-400), also supervisor for satellite communications for 777, and was manager of terminal-area projects (GLS, MLS, enhanced vision).