Abstract: Embodiments of the present invention are directed to a devices and methods for forming a desired miture of two or more fluids in a conduit. The devices and methods feature control means having error monitoring means and in response to an error event the control means organizes the packet-group of command signals to form at least one first error packet group. The error event occurs during the period of time in which the at least one error packet-group is received by a selectable value. The at least one error packet-group comprising an order or timing of first command signals and second commands signals to minimize deviation from the desired mixture in the flow of mixture-packets forming the desired mixture of two or more fluids in a conduit during the error event.