TCAS/ATC Transponder Control Panel
Transponder Mode Selector
STBY - TCAS and the transponders are in standby. Message TCAS STBY displays in green on upper ECAM.
XPDR - TCAS is in standby. During flight, the transponder is ON; on the ground, the transponder only responds to the selective interrogation mode of mode S.
TA - The transponder is ON. TCAS is on but only the traffic advisory function of TCAS is operational. Both resolution advisories and pitch guidance are inhibited. The message TA ONLY appears on the ND.
TA/RA - The transponder is ON and all TA and RA functions of TCAS are operational.
TFC - The TCAS/ATC system is ON and all transponder equipped airplanes within approximately 30 NM (40 NM range or less must be selected on some airplanes), and the altitude slice selected by the Altitude Range (ABOVE/N/BELOW) switch are displayed full time (Other, Proximate, TA, and RA traffic).