Sensors can be interfaced to any computer or processor-based equipment that contains a serial port when using the D5000 series of four-channel analog input smart data acquisition modules. The modules combine wide-range analog input signal conditioning, A/D conversion and communicate in ASCII via RS-232 or RS-485. As many as 31 modules or 124 channels can be strung on a pair of wire to a serial port on a host computer. The modules provide a low-cost front-end for industrial measurement and monitoring. Models are available to measure voltage, current, thermocouple and thermistor with RS-232 or RS-485 output. The measurement resolution if 15 bits and accuracy is ±0.02%. The internal, 8-bit microprocessor automatically performs zero and full-scale calibration tasks. A programmable digital filter is also included.