...Interoperability:
http://www.freyrscada.com/docs/FreyrSCADA-IEC-60870-5-101-Server-Interoperability.pdf
Download Evaluation Kit - IEC 101 Development Bundle:
In the Development Bundle, We included IEC 101 Server & Client Simulator, Windows and Linux Software Development Kit.
http://www.freyrscada.com/iec-60870-5-101.php
you can test the simulator
and use the serial null modem emulator (https://sourceforge.net/projects/com0com/) for connecting IEC server and client simulator via serial cable.
video tutorial:
https://www.youtube.com/playlist?list=PL4tVfIsUhy1bsVPrJVW4nknHozdfcWE5u