Figure F13. MEG system block diagram. Dashed lines = power distribution; thin lines = serial links; and thick lines = analog signal lines. DC = direct current; SAM = storage acquisition module; SWB = seawater battery; CRM = combiner/repeater module; PDM = power conditioning/distribution module; MOSFET = metal oxide silicon field effect transmitter; OBHS = ocean borehole seismometer; RS = receive/send; TTL = transistor-transistor logic; A/D = analog-to-digital converter; SIM = strainmeter interface module.