High-frequency measurements

High-frequency (square-wave) signals can be measured on terminals: 

• P or C

Common sensors that output high-frequency pulses include:

• Photo-chopper anemometers
• Flow meters

Measurement output optionss include counts, frequency in hertz, and running average. Note that the resolution of a frequency measurement can be different depending on the terminal used in the PulseCount() instruction. See the CRBasic help for more information.

The data logger has built-in pull-up and pull-down resistors for different pulse measurements which can be accessed using the PulseCount() instruction. Note that pull down options are usually used for sensors that source their own power.

P terminals

• CRBasic instruction: PulseCount()

High-frequency pulse inputs are routed to an inverting CMOS input buffer with input hysteresis. See Pulse measurement specifications for more information.

C terminals

• CRBasic instructions: PulseCount()

See Pulse measurement specifications for more information.