Between the Ashes is a mod set in the Freespace universe between the events of Freespace 1 and Freespace 2.
Only one scan allowed at a time. Paints yourself as hostile to the sentry when you start the scan. If the reprogramming is successful, the sentry becomes friendly. If not, it remains hostile.
Slasher did the bulk of the work. I (Mjn) simply made it work with something other than training messages and set it up so that you can only scan one sentry at a time.