RD-30 Operations ManualOperations Overview214.10 Serial Port Communications TerminalThe communications terminal is interfaced via a DB-9 connector. Through the use of thisterminal, a myriad of capabilities present themselves. Not only can each RD-30 software packagebe utilized, the RD-30 can actually be re-calibrated through this terminal. Additionally, the flashmemory storage for both the DSP and Xilinx programs is accessible through this terminal makingthe RD-30 field upgradable.4.11 Pickup TerminalThe sensor input terminal on the RD-30 comes in the form of a 4 Pin Lemo connector. RadianDisk sensors, infrared and visible LED optical pickups can be utilized to sense disk rotationor equivalent revolutions. See Section 2.1 Generating RD-30 Model Numbers for furtherinformation.4.12 Chasis Ground, Guard, NeutralChassis Ground ā ideally tied to the best available earth ground. If the RD-30 is mounted in arack, no connection is required. The Chassis grounds main purpose is for safety.