[Freeswitch-users] Delayed start of tone_detect

I start the tone_detect on answer using "execute_on_answer" as: <action application="export" data="nolocal:execute_on_answer=tone_detect MYTONE 680 ro +5000 set MYTONE=1" /> but I have the necessity to start the tone_detect for example 500ms after answer: there is a way to do that in dialplan?