The subject invention provides reliable messaging with and within a
control environment. The systems and methods utilize a message broker
that facilitates message exchange. The message broker can be located
within an industrial controller, as a dedicated entity within a control
environment and/or an entity external to the control environment.
Messages transmitted from an industrial controller and/or the external
entity can be routed through the message broker prior to reaching a
destination, wherein the message can be stored in the message broker and
subsequently obtained by a recipient. The message broker decouples the
message sender (e.g., an industrial controller, an external entity . . .
) from the message recipient (e.g., an industrial controller, an external
entity . . . ) such that messages can be successfully transmitted (to the
message broker) regardless of a state of the recipient, and messages can
be retrieved (from the message broker) regardless of a state of the
sender.