Continuous disconnect tone

Hi Dears

I have a Central with continuous disconnect tone and its Frequecy is 460 Hz
I’ve connected 2 Ext of this central to my Sangoma Fxo ports
Please let me know how Asterisk have to detect this disconnection tone?
"busydetect " doesn’t work and its clear because busydetect , detect only regular sound-silence and not continuous tone
Also hanguponpolarityswitch=yes doesn’t work
I use Asterisk
Please help me