  The electronics of the CMS Drift Tube (DT) chambers need to be replaced
during Long Shutdown 3 to tolerate the High Luminosity LHC (HL-LHC) data taking
conditions. The first DT prototypes of the HL-LHC electronics, the on-detector
board (OBDT), have been installed in the DT chambers of one sector, out of 60
sectors, and integrated into the central data acquisition and trigger systems.
The signals from the chambers are split and reach both the legacy and Phase-2
demonstrator chains, which will allow them to operate in parallel during LHC
collisions.
