Abstract: Disclosed is a release tool used to separate portions of a tool string. One release tool includes a main body, a collet retainer coupled to the main body and having a collet assembly arranged therein, the collet assembly being operatively coupled to a lower sub, a support piston releasably coupled to a separation nut and engaging the collet assembly such that the lower sub is prevented from removal from the collet assembly, and a trigger mechanism configured to send a command signal to the separation nut whereupon the separation nut releases the support piston such that it is able to be moved and the lower sub is thereby able to be removed from the collet assembly.