IEC-60870-5 application layer over TCP/IP for an open and flexible remote unit

This paper presents the development and test of the standard IEC-60870-5 application layer protocol over TCP/IP for a remote terminal unit (RTU) based on open hardware and software. The RTU hardware is an embedded system, a SoC-type design using FPGA that has been programmed with the open core LEO/ with Linux operating system running over it, so both the and IOS are open source. For prototyping the GR-XC3S-hardware 1500 board has been used. There is no open source code available for the IEC standard protocols, so application layer protocol over TCP/IP has to be implemented. All the software design has been made in a PC platform using standard development tools. The source code generated for the protocol has been compiled with the standard Linux gcc compiler in LEON. Several tests have been made to prove that the RTU works correctly.