A metering system configured to couple to multiple specialty systems, such as a control system. At least some of the illustrative embodiments are processing units comprising a processor, a memory coupled to the processor, and a communication port configured to coupled to a backbone communication network of a control system. The memory stores a program that causes the processor to selectively participate (over the communication port) as a processing unit of a control system of a first manufacturer (the control system implements a first proprietary communication protocol between processing units), and to participate (over the communication port) as a processing unit of a control system of a second manufacturer different than the first manufacturer (the control system of the second manufacturer implements a second proprietary communication protocol between the processing units).