| 摘要 |
FIELD: instrument engineering. ^ SUBSTANCE: proposed invention refers to automated process control systems, and namely to field transmitters operating in nominal mode or in self-diagnostic mode. Field signal transmitter includes the following: physical sensor for measuring process parametre and for generating analogue physical sensor signal, which represents process parametre; surrogate sensor for generating analogue signal of surrogate sensor, which is independent of process parametre; signal processing scheme that converts an analogue input signal into digital measurement result; supply means of analogue physical parametre of sensor as analogue input signal to signal processing scheme during standard mode, and supply means of analogue parametre of surrogate sensor as analogue input signal to signal processing scheme during diagnostic mode; storage means of expected digital value of digital measurement during diagnostic mode; output signal transmission means via communication channel as function of digital measurement result, which is obtained during standard mode; and diagnostic evaluation means of signal processing scheme based on comparing digital result of measurement made during diagnostic mode to stored expected digital value. There have been implemented several modifications of similar transmitter. ^ EFFECT: this invention allows performing self-diagnostics of field transmitter during operation thereof. ^ 10 cl, 5 dwg |
