High speed counting with the MotionIn function
MOTION-IN is used for high speed counting of digital input signals. It’s a background task. Once a MOTION-IN Block is executed, it’ll continue counting in the background until another MOTION-IN block set to Stop is executed.
To enable MOTION-IN, Press the “Setup Hardware” button. It’s on the upper left of vBuilder.
The last page of the “Setup Hardware” lets you set MOTION-IN (High-Speed Counter) options.
There are 2 MOTION-IN types: Pulsed input and quadrature input. Shown below is the setup pages for MOTION-IN type.
Pulsed input : Typically is associated with frequency, counting or totalization applications
Pulsed input requires 1 Digital Input. After configuring in “Setup Hardware”, placing a MOTION-IN Block brings up the following Dialog.
The Tag you select for “Count Value” will store the MOTION-IN’s count value. Count Value must be of the I32 Data Type. The MOTION-IN block can be set to count up or down. A count is triggered by either a rising (0 to 1) value, or a falling (1 to 0) value. The “Counter Input Bit” that causes the count is the digital input that you selected in “Setup Hardware”.
Quadrature Input (A and B signals) : Provides the interface to incremental encoders for obtaining mechanical position data
Quadrature Inputs are used with incremental rotary encoders.
The type of quadrature encoding of the MotionIn function is the X4. Both the rising and falling edges of both channels, A and B, are counted
Check out Wikipedia’s article on them to learn more. They require 2 digital inputs. Be sure not to use the same digital input for both quadrature inputs.
Start counter :
Start counter requires an I32 tag to store the count in.
Stop counter :