OpenPLC is an open-source software that complies with IEC 61131-3 international standard and has been widely used by researchers to validate PLC logic execution. However, the software’s capability is limited as it is solely restricted to Modbus and DNP3 protocols. With the integration of intelligent electronic devices (IEDs) into modernized power grid based on IEC 61850 standards, it is necessary to incorporate functionalities that enable PLCs to communicate with IEDs. Therefore, in this paper we develop OpenPLC61850, which is an extended version of OpenPLC and is compatible with the IEC 61850 protocol. The architecture and the procedure involved with PLC logic execution, IED communication, and SCADA connectivity are explained in this paper. As the proposed software is also an open source, we believe that this would be helpful for researchers for conducting smart grid research.