Campbell CR310 User Manual

Switch Closure on P Terminal Open Collector on P Terminal
18.5.3.2 C terminals
Switch-closure measurements on C terminals require a 100 kΩ pull-up resistor to 12 V. Switch-
closure mode is a special case edge-count function that measures dry-contact switch-closures or
open collectors. The operating system filters bounces.
l
CRBasic instruction: PulseCount().
See also Power output specifications(p. 242).
18.5.4 Quadrature measurements
The Quadrature() instruction is used to measure shaft or rotary encoders. A shaft encoder
outputs a signal to represent the angular position or motion of the shaft. Each encoder will have
two output signals, an A line and a B line. As the shaft rotates the A and B lines will generate
digital pulses that can be read, or counted, by the data logger.
In the following example, channel A leads channel B, therefore the encoder is determined to be
moving in a clockwise direction. If channel B led channel A, it would be determined that the
encoder was moving in a counterclockwise direction.
18. Measurements105

Campbell CR310 Specifications

General

Brand	Campbell
Model	CR310
Category	Data Loggers
Language	English