MULTICHANNEL FREQUENCY METER ON A PROGRAMMABLE LOGICAL INTEGRATED CIRCUIT FOR A RADIOMEASURING SYSTEM WITH FREQUENCY SENSORS

Abstract

The paper presents the development of a multi-channel frequency measurement system on FPGA by Altera Cyclone IV, the main task of which is to measure the informative parameter of sensors of physical quantities with frequency output. Based on the analysis of existing multi-channel frequency measurement systems on the FPGA, it is established that it is advisable to use multi-channel frequency meters for simultaneous measurement of several frequencies. Unlike several frequency meters operating simultaneously, multi-channel frequency meters perform measurements in a single time base, which is provided by a common exemplary generator and timer. A multi-channel universal FPGA-based measuring device has been developed, which has 12 measuring channels for frequency output sensors and supports simultaneous operation of 127 digital sensors via I2C interface. Therefore, theoretically, data transmission from the developed device can be carried out wirelessly. The developed device can be connected to a personal computer via a UART-USB converter. As a chip for the implementation of the frequency meter is used FPGA company Altera EP4CE10F17C8 – a chip in the BGA case, which has 179 pins. The parameters, namely the value of the signal propagation delay, determine the maximum measured frequency, in our case about 3 ns (delay of the signal from the input to the internal register), which corresponds theoretically to 333 MHz. Specialized software has been developed to test the efficiency of a multi-channel measuring system for measuring informative parameters obtained from radio measuring transducers, based on the reactive properties of semiconductor structures with negative resistance. For convenience of perception, there is a visualization of the received information from the measuring device.