Central Manufacturing Technology Institute, Bangalore, India was using Raytheon precision laser driller/welder which was manufactured around twenty years back. The laser system was manufactured using analog controllers. The company is finding difficulty in procuring analog components which was used twenty years back, during maintenance and feature up gradation. Analog controllers are non-expansible and troubleshooting is difficult. Hence the company want to replace the existing analog controller with any digital controllers. The paper deals with simulation of the system working and safety features using PLC software Zeliosoft2 v4.5 in order to validate that the analog controller could be replaced by digital controller.