For the two-wire RTD measurement, set these registers:
- Select multiplexer settings for AINP and AINN to measure leads 1 and 2 of the two-wire RTD
- Enable the PGA, set gain to desired value
- Select data rate and digital filter settings
- Select reference input to measure RREF for ratiometric measurement
- Enable the internal reference (the IDAC requires an enabled internal reference)
- Set IDAC magnitude and select IDAC1 output pin to drive lead 1 of the first RTD
For the three-wire RTD measurement, set these registers:
- For the first measurement, select multiplexer settings for AINP and AINN to measure leads 1 and 2 of the three-wire RTD
- Enable the PGA, set gain to desired value
- Select data rate and digital filter settings
- Select reference input to measure RREF for ratiometric measurement
- Enable the internal reference (the IDAC requires an enabled internal reference)
- Set IDAC magnitude and select IDAC1 output pin to drive lead 1 of the first RTD
- For the second measurement, select the multiplexer settings for AINP and AINN to measure leads 2 and 3 of the three-wire RTD
- Subtract the second measurement from the first measurement
For the four-wire RTD measurement, set these registers:
- Select multiplexer settings for AINP and AINN to measure leads 2 and 3 of the two-wire RTD
- Enable the PGA, set gain to desired value
- Select data rate and digital filter settings
- Select reference input to measure RREF for ratiometric measurement
- Enable the internal reference (the IDAC requires an enabled internal reference)
- Set IDAC magnitude and select IDAC1 output pin to drive lead 1 of the first RTD