A surgical tool that includes a sterilzable hand piece that receives an aseptic power module. The hand piece includes a data tag that contains data identifying the type of hand piece. The power module includes a reader that reads the data from the data tag. Based on the type of hand piece the power module selectively actuates the power generating unit internal to the power module. Specifically, the power generating unit is actuated to output energy having the appropriate characteristics for the type of hand piece to which the power module is attached. In many versions of the invention, the data tag is mounted to the latch integral with the hand piece. The power module also interprets the receipt of the data from the hand piece as an indication that the power module is properly latched into the hand piece.
