Difference between Queue and Notifier , how it use in LAbview Programming

[MDPatil]

What difference between Queue and Notifier , how it use in LAbview Programming?

please exaplain?

Manohar

[crossrulz]

The main difference is that a Queue is a FIFO and a Notifier is a single value.  So a Queue is typically used for a Many-to-One communication (many writers and 1 reader) while a Notifier is typically used for a One-to-Many communication (1 writer, many readers).

[altenbach]

... and since this is a plain LabVIEW question, posting in the counter/timer forum seems misplaced. What was your reason to post here? Is there more to your question?

[udka]

Adding to crossluz comments,Please check this thread also http://forums.ni.com/t5/LabVIEW/User-Events-vs-Queues-vs-Notifiers/td-p/1289138

[vaibhav24121988]

Thanx to all ....Smart and helpfull info...

[Sri.VI]

Thanks.....

Nice explanation.... So , i can use use Notifiers to control Multiple Loops with a single Command and using queue can record all the data from many loops to single variable... is this statement correct?

[crossrulz]

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@Sri.VI wrote:

Thanks.....

Nice explanation.... So , i can use use Notifiers to control Multiple Loops with a single Command and using queue can record all the data from many loops to single variable... is this statement correct?

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That is one way to put it.

[Korpz]

I realize this is an old topic, but thought I would ask a question......

If I am using a serial connection (COM Port) and I want a few VI's running in parallel that access that said COM port, should I use Queue or Notifier? Obviously, the COM port can only be accessed one at a time,

Thanks,

Ryan

[PalanivelThiruvenkadam]

Just Adding Points in my VIEW

Notifier Follows a broadcasting Mechanism where N Number of listeners Receive the value until the new value is written, where Queue Does not follow broadcasting mechanism as the Queued Value is De Queued once, then the value wont be available for other listeners.

One better option is create a FGV and hold the COM PORT Ref in the FGV and can be used wherever needed.

[crossrulz]

A Queue is good for N to 1 communications where every value must be processed.

A Notifier is good for N to N communications where only the latest value matters.

An Action Engine would be a good route to go as well.  The AE can have actions for initializing the port, a simple write command, a query (write and then read the response), and close the port.  This would help make sure your transactions are protected from being interrupted by other processes trying to access that serial port.