NI Qbus is a LabVIEW based messaging API. The library provides VIs for sharing messages between asynchronous processes. The Qbus API provides subVIs that allow processes to send two types of messages:

Broadcast messages—Available to any process. The sender does not specify a recipient for a broadcast message. To receive a specific type of broadcast message, each process registers for the messages it desires by name.

Routed messages—Sent only to a specific, named process. You might send a routed message when multiple processes register for a particular message name, but in a specific situation, you only want one specific process to receive and handle the message.