ScheduledWANDisconnect
From MikroTik Wiki
"t-dsl" is the name of the WAN-interface, PPPoE in this case
/ system scheduler add name="sched_disconnect" on-event=pppoe_dis start-date=jan/01/2006 start-time=03:00:00 interval=1d \ comment="move daily T-DSL-disconnect to late night" disabled=yes /system script add name=pppoe_dis source={/interface pppoe-client disable [find name="t-dsl"] :delay 10 /interface pppoe-client enable [find name="t-dsl"] :log info "Script pppoe_dis - scheduled T-DSL-disconnect executed." }
should be tested in your environment and use it by own risk!
....or simply name your pppoe interface "ADSL" and do it within scheduler without scripting ...
/system scheduler add name="ADSL reconect" interval=1d on-event="interface pppoe-client disable ADSL ;\r\ \ninterface pppoe-client enable ADSL ;\r\ \n" policy=ftp,reboot,read,write,policy,test,winbox,password,sniff,sensitive,a start-date=sep/12/2012 start-time=06:00:00