As per the Seebeck Effect, temperature differences across metal will produce a voltage. This voltage is measured by the PXIe-4353, and this effect shows that the voltage is directly proportional to the temperature at the hot junction minus that of the cold junction. This is shown by the following calculation:
V = 𝜶 (THJ - TCJ)
where V = voltage, 𝜶 = Seebeck coefficient for the metal used for the thermocouple, THJ is the hot junction temperature, and TCJ is the cold junction temperature.
As such, the device will measure the voltage coming in, use the appropriate 𝜶 value based on the thermocouple type chosen and the cold junction temperature defined by the CJC Source to calculate the temperature observed (THJ).