CA51/CA71 is a Yokogawa company's fieldbus adapter for thermocouple (TC) and resistance temperature detector (RTD). CA51 communicates with the host via RS-232C serial port, while CA71 communicates with the host via Ethernet (TCP/IP). CA51/CA71 can connect one or more TC/RTD modules, and output 4-20mA current signal. The module supports up to 32 TC/RTD input signals, with a measurement range of -200°C to 600°C. The module adopts a plug-in design for easy installation and maintenance.