A method and software interface enables serial data streams to be trapped, parsed, tested for suitability for automated handling by a medication preparation system. Only those portions of the serial data stream that are not suitable for such handling are released for printing and manual handling. A serial data interface includes a listener software module ("LSM") that receives serial data streams and a parser software module ("PSM") communicatively connectable to the LSM that processes the serial data streams received from the LSM. A set of configuration rules accessible by the PSM defines the manner of processing by the PSM on the serial data streams. A data structure results that enables data handling by an automated medication preparation system.