Apollo CNX80 Pilot’s Guide24Transponder Control (XPDR)If a remote Apollo SL70 transponder is connected and setup to oper-ate with the CNX80, the Transponder Control Mode will allow you tocontrol your transponder from the CNX80 front panel. Press XPDR toactivate Transponder mode.IdentPress the IDNT key once to activate the Ident mode. The key label willbe highlighted and an IDNT annunciator will appear by the squawkcode for 20 seconds.StandbyPress the STBY key to place the transponder in Standby mode. Noinformation will be transmitted while in Standby mode. A SBY annunci-ator will appear to the left of the squawk code.ONPress the ON key to enable Mode A operation, which shows the four-digit squawk code. An ON annunciator will appear to the left of thesquawk code.AltPress the Alt key to enable Mode C operation, which also sends alti-tude data along with your squawk code. An ALT annunciator willappear to the left of the squawk code.Transponder Line Selection KeysPress the Menu/Enter key to display the keys on the right side of thescreen.EmergencyPress the Emrgncy key to select the emergency 7700 squawkcode.XPDR