This thesis describes the making of a Beckhoff stepper motor library for Siemens programmable logical controllers made in Siemens TIA Portal software. The main goal was to create a program block that simplifies programming automatic lines with Beckhoff stepper motors installed. The motive for making the library, the solutions made so far and the initial requirements of the task are described in the beggining. Next is a specification comparison of the new and the old motors and their price difference on different setups. After that I talk about core concept of the new library, the selection of the testing hardware and then I expain library's source code and its purpose. My comment, furher plan for inpruvements and all the troubles that occur will be defined in the last section.