... Counter2.1 Features With CPU and IC-counter,intelligent,wide range,multifunction,highbright 8 digit LEDs display. Measurement functions:frequency:A,B, ... B,A→B and intenal frequency.A,B with attenuators and LPF.2.2 Specifications2.2.1 Frequency measurement range CHA,CHB ... Features Auto range,LCD display with digit and strip figure to show,multiparmeter test and with RS232C interface.4.2 Specifications DC ...