Functions Palette/Programming/Synchronization/Queue Operations

Queue Operations palette (Click on a function to navigate, or on the arrow to go to parent palette)

Object information
Owning palette(s)	Synchronization palette
Type	Palette
Requires	Basic Development Environment

Use the Queue Operations functions to create a queue for communicating data between sections of a block diagram or from another VI.

Unlike the Notifier Operations functions, the Queue Operations functions buffer data.

Functions

Icon	Name
	Obtain Queue
	Enqueue Element
	Preview Queue Element
	Get Queue Status
	Release Queue
	Lossy Enqueue Element
	Enqueue Element At Opposite End
	Dequeue Element
	Flush Queue

History

Version	Change(s)
	More info to come.

Concept

(From NI.com)

A queue maintains a first in/first out (FIFO) order of data items. For instance, the customers waiting in line at a fast food restaurant are in a queue.

A queue is useful in producer/consumer situations, where one portion of code is creating data to be used by another portion. The advantage of using a queue is that the producer and consumer rates do not have to be identical. If consumption is slower than production, the queue will become full and the producer code will be forced to wait until the consumer has dequeued an element before a new element can be queued up.

Unlike an array, it is not possible to randomly access elements in a queue. It is strictly a buffer that provides you the ability to enqueue (add/insert) and dequeue (subtract/remove) elements. The only way to view all the elements in a queue is to dequeue them one by one. You cannot perform data manipulation to all the elements in a queue either.

Example use cases

Queued State Machines (Also known as Queue Driven State Machines, or QDSMs).

External Links

1. NI.com - What Is a Queue