Most satellite dish actuators send a series of pulses to indicate their position. By counting pulses the positioner knows where the dish is pointing. It is possible to use a serial port and Linux with RTAI patches in order to count these pulses, thus

In the measurement of frequency is actually 1s to count time signal, numerical is signal frequency. Using single-chip microcomputer frequency plan by using two kinds of method, usually the first approach is to use own counter chip counting input puls