Sentence:  The output signal of the multi-vibrator pulse-shaper circuit was the impact-event counting pulse. Its constant parameters provide a better form of input signal for the counting and storing <WSD>circuitries</WSD> than the originally tranduced inpact signal. The status of the impact event-counting and storage <WSD>circuitries</WSD> was telemetered whenever the satellite transmitted its data. 
Meaning of the word marked with <WSD> tags:  A specific system of electrical circuits in a particular device;  the design of such a system.