Read
- Updated2025-07-28
- 2 minute(s) read
Returns a message from the queue.
To read a message, you must subscribe to the topic the message is published to. If you do not subscribe to the topic, you cannot receive the message. Therefore, you cannot read it.
If there are no queued messages, the call synchronously blocks up to the timeout specified or to the maximum timeout the web service defines, whichever is smaller. The SystemLink Server times out after 10 seconds.

Inputs/Outputs
message session in
Synchronous message session established with the server.
timeout
Time, in milliseconds, that this node waits for an enqueued message before timing out.
Default value: 100
error in
Error conditions that occur before this node runs.
The node responds to this input according to standard error behavior.
Default value: No error
message session out
Synchronous message session established with the server.
topic
Channel to which endpoints publish or subscribe messages.
Ensure topic names are unique to avoid name collisions.
message
Text published for subscribers of a topic to read, if a message exists.
error out
Error information.
The node produces this output according to standard error behavior.
dequeue status
Information about the current state of the node.
If True, the node received an incoming message. If False, the node timed out.