Application of an Embedded TCP/IP Protocol in a Dewar Performance-Parameter Monitoring System of a Radio Receiver

This paper gives the design and implementation of a monitoring system for the temperature and vacuum degree of the dewar of an astronomical radio receiver. We discuss the details of the hardware structure of monitoring and the embedded TCP/IP. Following the current wide-spread use of 8-bit microcontrollers the embedded system uses the controlling chip ATmega16 produced by the ATMEL and an independent Ethernet microcontroller ENC28J60 with SPI interface produced by the Microchip. The monitoring system based on Ethernet has low cost, high efficiency, and high stability. Test results show that the system can transmit data highly effectively with personal computers (PCs).The error of temperature value received by a PC is within ±0.3 K, and the error of the vacuum-degree value received by a PC is within ±10 ubar. These can meet the system design requirements.