Hey There
First up there is NO such thing as "Tank" firmware. Er9X and ersky9x have come such a long way that a separate edit for tanks is no longer necessary. Please use the latest and greatest versions of er9x (9X and 9XR) or ersky9x (9XR Pro, 9Xtreme) These are available from:
www.er9x.comalso on the site is a link to the er9x manual (top right on page). This manual can be used for BOTH er9x and ersky9x.
Whatever, is on er9x.com is the latest public release. The latest "test" releases are here:
http://openrcforums.com/forum/viewtopic ... d83942977fThe alarm/alert you are refering to is the throttle alarm. You can read up about it on page 17 of the manual.
Cheers
Kevin G