An Ethernet-based Monitoring System of Cryogenic Receivers on a Radio Telescope

A cryogenic receiver is a key equipment on a radio telescope.The temperature of cryogenic receiver and the vacuum level of its dewar are two important factors for measuring whether the receiver works properly and thus whether the radio telescope functions normally.Therefore,it is necessary to monitor the temperature and vacuum level of the cryogenic receiver.We designed and made a remote-monitoring system for a new 1.3cm dual polarization cryogenic receiver,which will be installed on the 25m radio telescope of the Urumqi Station.This paper describes the method of how to design and make this system.The monitoring system is controlled by a single-chip microcomputer.The system acquires data,transfers data,and remotely monitors the radio astronomical receiver via an ethernet.The microcomputer,ethernet controller,and drive circuit of the system are the 8-bit MCU AVR ATmega16, ENC28J60, and MAX7219,respectively.The system monitors the cryogenic receiver by reading its temperature and vacuum level of dewar.This system includes the network interface circuit,microcontroller circuits,RAM memory circuit, and EEPROM memory circuit.Overall,the system achieves remote real-time monitoring of the working status of a cryogenic receiver on a large radio telescope for the first time in China.It is particularly important for ensuring the effective observation with the 25m radio telescope at the Urumqi Station through 1.3cm wavelength bands.