Campbell CR6 Series, Operator'S Manual

Page: 444 / 690

Section 8. Operation
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frequency. Sensors that commonly output a switch closure or open-collector
signal include:
• Tipping-bucket rain gages
•
Switch closure anemometers
•
Flow meters
Data output options include counts, frequency (Hz), and running average.
An internal 100 k
Ω
pull-up resistor pulls an input to 5 Vdc with the switch open,
whereas a switch closure to ground pulls the input to 0 V. An internal hardware
debounce filter has a 3.3 ms time-constant. Connection configurations are
illustrated in table
.
•
Maximum input f requency = 90 Hz
• CRBasic instruction:
PulseCount()
8.1.3.5 Edge Timing
Edge time and period can be measured on U or C terminals. Applications for edge
timing include:
• Measurements for feedback control using pulse-width or pulse-duration
modulation (PWM/PDM).
Measurements include time between edges expressed as frequency (Hz) or period
(µs).
U and C Terminals
•
See
Edge Timing — Specifications
(p. 113).
• CRBasic instruction: TimerInput()
8.1.3.6 Edge Counting
Edge counts can be measured on U or C terminals.
U and C Terminals
• See Edge Counting — Specifications
(p. 113).
o CRBasic instruction: TimerInput()
8.1.3.7 Timer Input on I/O NAN Conditions
•
NAN is the result of a TimerInput() measurement if one of the
following occurs: