LabVIEW
Producer-Consumer very basic help and advise
Dear All.
As said before I am learning LabVIEW and only did the basic 1 level please take it easy on me.
I am working on a small application that sends a CAN message out and receive 2 Messages back the cycle time is 10mSec both ways.
I my limited knowledge I managed to find the information regarding using a Producer Consumer pattern to pass the data between the 3 loops( 1 main loop ,2 timed loops),I found in LabVIEW the template however there as few sub Vi's and shift registers with virtually no comments or an description how it works,I also do understand that the template is actually for people that has the background knowledge(which I am missing) ,My request is for a pointer to some material very basic that can help me understand how to pass 4 bytes from the main loop to the CAN send loop and pass 4 bytes of data from the CAN receive loop back to the main loop.
All help is very highly appreciated
Regards QMESAR
Hi All,
I am digging into all of these synchronization topics ,I have worked through a few examples of Notifiers and Queues,
One issue that I am having and would appreciate if someone can help me understand I found a simple example of passing a Queue to a parallel loop the wire color for the Queue in the example are orange and green when I do the same in my own VI then my Queue wire color is the same blue as in the case of a Notifier .
Am I doing something wrong ?
The wire color of the example
My wire Color for the Queue
Secondly so far I have learned that the execution of the consumer loop is dependant on the availability of the Notifier or the Queue meaning that the Consumer loop only execute when data is there practicaly the consumer loop execute at the same rate as the Producer if the producer execute every 100mSec then the Conumer execute every 100mSec's the only difference between the Notifier and the Queue is the buffered data by the Queue thus if the consumer executes a bit slower that the Producer loop no data is lost as the consumer reads from the buffer However in my case I would like the Consumer to execute every 10mSec and the producer deliver new data every 100mSec ,Still trying to find the correct information.
Also using a Timed loop as the Consumer loop so far did not work for me as once I use the Queue method the Timed loop execute at the rate of the producer loop and not at the Timed loop preset Time is it actually doable using a Timed loop with Queue's
I appreciate any help or advise
Regards
QMESAR
@QMESAR wrote:
Secondly so far I have learned that the execution of the consumer loop is dependant on the availability of the Notifier or the Queue meaning that the Consumer loop only execute when data is there practicaly the consumer loop execute at the same rate as the Producer if the producer execute every 100mSec then the Conumer execute every 100mSec's the only difference between the Notifier and the Queue is the buffered data by the Queue thus if the consumer executes a bit slower that the Producer loop no data is lost as the consumer reads from the buffer However in my case I would like the Consumer to execute every 10mSec and the producer deliver new data every 100mSec ,Still trying to find the correct information.
Regards
QMESAR
You can have several producers, that's one of the key design ideas of a queue, Many-to-one. In your case, if you want to read/sample something every 10ms, make that a loop of its own, and send/enqueue it to the consumer, which'll then handle/keep track of things, like saving to file or displaying a graph.
As for the wire color, i think it's always a green outline surrounding the data type. In your integer array the thick blue should have a green border, but i might be misremembering.
/Y
