What is this icon?

[Jyo263]

How to get one of these??

[altenbach]

One way: Create a queue of the right type, right-click the queue output, and "create constant".

[pincpanter]

This is a Queue reference constant where the queue element type is the predefined type (a string). To create it, paste any queue function on the BD, right click on the queue or queue out terminal and then select Create > Constant from the context menu

[Jyo263]

Is the queue element type a string cluster??

[pincpanter]

A queue element can be of any type. In this specific case is a String.

There is no such thing as a String Cluster. A Cluster is a container in which you can put a series of controls of several types. In a Cluster, you may even have a single String and nothing else (although usually it makes little sense). A Cluster with a single String control, however, i not the same as a String control alone.

I guess you should go through the LabVIEW tutorials as these are really basic information.

[altenbach]

The queue element is a mixed cluster (pink) having elements differing in datatype. A purely numeric cluster would be brown.