A telemetry system for transferring blocks of pulsed data signals to and from daisy chains of addressable data ports. The telemetry system includes a daisy chain of input data ports and a parallel daisy chain of output data ports; an output data line and an input data line each serially-connecting the data ports; a clock signal generator for generating square wave clock pulses for common system timing; and a clock line for carrying the clock pulses to the ports. Each data port contains an address circuit which determines when during each block of serially-transmitted data signals that port is enabled to transfer data independent of its physical location on the data line. Data signals are transmitted over the data lines during high-state intervals of the clock signal and control signals such as frame signals, are transmitted over the data lines during the low-state intervals of the clock signals. The data ports demultiplex received data/control signals received over the data line for data transfer operations and internal control, regenerate the received signals for further transmission to distant data ports in the chain, and multiplex the regenerated data and control signals onto the data line for such further transmission. The system is also capable of determining the serial location of a data port where a failure has occurred.