The IS200EISBH1A developed by General Electric is a PCB component for the Mark VI. The Mark VI is part of the Speedtronic family of gas/steam turbine management. The Mark VI is built to as a complete protection, control and monitoring solution for turbine systems of varying size and application. This component is known as an Exciter ISBus Board and is a special Communication Interface board that works within the M1, M2 and C control Modules. It is used in many GE systems and functions as a high-speed proprietary communication bus. This board also uses its backplane connector to receive and transmit fiber-optic feedback signals and then transmits them over the control backplane to the DSPX control.