An experiment that measured the parity-violating asymmetries in deepinelastic scattering was completed at the Thomas Jefferson National AcceleratorFacility in experimental Hall A. From these asymmetries, a combination of thequark weak axial charge could be extracted with a factor of five improvement inprecision over world data. To achieve this, asymmetries at the $10^{-4}$ levelneeded to be measured at event rates up to 600 kHz and the high pion backgroundtypical to deep inelastic scattering experiments needed to be rejectedefficiently. A specialized data acquisition (DAQ) system with intrinsicparticle identification (PID) was successfully developed and used: The pioncontamination in the electron samples was controlled at the order of $2\times10^{-4}$ or below with an electron efficiency of higher than 91 % during mostof the production period of the experiment, the systematic uncertainty in themeasured asymmetry due to DAQ deadtime was below 0.5 %, and the statisticalquality of the asymmetry measurement agreed with the Gaussian distribution toover five orders of magnitudes. The DAQ system is presented here with anemphasis on its design scheme, the achieved PID performance, deadtime effectand the capability of measuring small asymmetries.
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