Module 1 (NI-9401) 

• 8 channel digital I/O set up as a pulse counter.
• Used to monitor pulses from anemometers
• Terminal block in the upper right provides power (through a resistor) to the anemometers.

Module 3 (NI-9205)

• 16/32 channel +/-10V analog input
• First 16 channels set up in +/-1V differential mode for the pyranometers and quantum sensors
• Last 16 channels set up in +/-5V referenced single ended mode for the HMP45 temp/RH sensors
• Common is tied to the 12VDC power supply negative terminal (for RSE channels)

Module 5 (NI-9213) 

• 16 channel +/- 75mV differential analog input
• First four channels measure light sensor signals
• Channel 5 measures voltage of the PT100 thermistor
• Common is tied to the shields and the 12VDC power supply negative terminal (for PT100)

0.5mA current source

• Provides approximately constant 0.5mA current for the PT-100 thermistor
• 0.5mA chosen to put the signal voltage within range of the NI-9213 AI module (approximately 50mV)

Anemometer terminal block

• Provides 5VDC, through a resistor, to the anemometers
• 5V chosen to match the TTL level of the NI-9401 DIO module