Hi,
definately NOT to a digital input! You should connect it to the power negative cable AND one of USB-6211 DGND pins. By the way USB-6211 also has a 5V output, so you wouldn't need the external power supply.
As far as I see from the sensor's specs it provides you a the temperature in digital format (12bit). Means you have to perform a digital input task and analyze the bits (Data->DigIN Pin). There are some obstacles if you plan to do so. E.g. there is no HW clock connected directly to the digital inputs so you have to do something like this:
Correlated DIO with USB M Series DAQ Device - National Instruments
http://digital.ni.com/public.nsf/allkb/D34BEC815E400ECD8625768A006F8AD6
Afterwards you also have to find the start of a transmission and alnalyse the bits.
What you plan to do is possible but in my opinion you shoud reconsider your choice of temperature sensor and by one which delivers you a to the temperature proportionl voltage, then spimply perform an analogue input task...
Hope I could help you
Heinz
