The Servo Board (VSVO) controls four electrohydraulic servo valves that actuate the steam/fuel valves. These four channels are divided between two TSVO terminal boards. Valve position is measured with linear variable differential transformers (LVDT). Three cables to VSVO use the J5 plug on the front on the board and the J3/4 connectors on the VME rack. TSVO provides Simplex signals via the JR1 connector, and fans out TMR signals to the JR, LS, and JT connectors. Plugs JD1 or JD2 are for external trip from the protection module.