![labview queue labview queue](https://i.ytimg.com/vi/cLihjvyaxAM/maxresdefault.jpg)
#Labview queue code#
Figure 1 illustrates how the Producer/Consumer design pattern can be created in LabVIEW.įigure 1: Producer/Consumer Design Pattern Note: This image is a LabVIEW snippet, which includes LabVIEW code that you can reuse in your project. Because queues are first-in/first-out, the data will always be analyzed by the consumer in the same order as they were placed into the queue by the producer. The consumer loop will be removing data from that queue (removing data from a queue is called “dequeue”). Because the producer loop produces data for the consumer loop, it will be adding data to the queue (adding data to a queue is called “enqueue”). In the Producer/Consumer design pattern, queues can be initialized outside both the producer and consumer loops. Queues are based on the first-in/first-out theory. LabVIEW has built-in Queue Operation VIs found in the Functions palette > Data Communication > Queue Operations. Communication between producer and consumer loops is done by using queues or channel wires. The Producer/Consumer design consists of parallel loops which are broken down into two categories producers, and consumers. These queues offer the advantage of data buffering between producer and consumer loops. Data queues are used to communicate data between loops in the Producer/Consumer design pattern. The Queued Message Handler architecture is a specialized version of the Producer/Consumer architecture. With buffering, packets can be retrieved and communicated faster than they can be analyzed. This buffering will become very important when network communication gets busy. The parallel producer and consumer loops will handle the retrieval and analysis of data off the network, and the queued communication between the two will allow buffering of the network packets retrieved. This application would benefit from the use of the Producer/Consumer design pattern. In this example, the first process will act as the producer because it is supplying data to the second process which will act as the consumer. Network communication requires two processes to operate at the same time and at different speeds: the first process would constantly poll the network line and retrieve packets, and the second process would take these packets retrieved by the first process and analyze them.
![labview queue labview queue](https://i.stack.imgur.com/YH9de.png)
This will allow the consumer loop to process the data at its own pace, while allowing the producer loop to queue additional data at the same time.Ĭonsider – if both the producer and consumer are in the same loop for this application, the data acquisition speed slows to match the speed of processing the data. This is why is it beneficial to break up your code by process, data acquisition (Producer) and processing (Consumer). Because queuing up (producing) this data is much faster than the actual processing (consuming), the Producer/Consumer design pattern is best suited for this application. Suppose you want to write an application that accepts data while processing them in the order they were received. The Producer/Consumer pattern is commonly used when acquiring multiple data sets to be processed in order. To visualize the buffered communication that occurs when using the Queue functions, see the example program Move LabVIEW Window Using Producer/Consumer Loops Data Acquisition and Processing
![labview queue labview queue](http://i.ytimg.com/vi/SJRuIgmblTc/maxresdefault.jpg)
This ability to buffer data will minimize data loss. With a large enough communication queue (buffer), the network process will have access to a large amount of the data that the data acquisition loop acquires. If the Producer/Consumer design pattern is used to implement this application, the data acquisition process will act as the producer and the network process the consumer. The first process operates at three times the speed as the second process. With a large enough buffer, the producer loop can run at much higher speeds than the consumer loop without data loss.įor example, consider an application has two processes – the first process performs data acquisition and the second process takes that data and places it on a network. When there are multiple processes running at different speeds, buffered communication between processes is extremely effective. The Producer/Consumer pattern gives you the ability to easily handle multiple processes at the same time while iterating at individual rates.