IS215VPROH1A is a Turbine Protection Board and is part of the GE Speedtronic Mark VI gas turbine control system. The Emergency turbine protection (VPRO) board and associated terminal boards (TPRO & TREG) provide an independent emergency Overspeed protection system. The Protection system consists of triple redundant IS215VPRO boards in a module separate from the turbine control system, controlling the trip solutions through (TREG) boards. IS215VPRO also has an Ethernet connection for IONet communications with the control modules. The original IS215VPROH1A has been superseded by the functionally equivalent to H1B. The VPRO (H1A & H1B) supports a second (TREG) board-driven from VPRO connector J4. H2B is a lower power version of IS215VPRO that omits support for the second TREG board.