Energy Metering consists of several components.
1. Metering Devices - This is the physical hardware that will read in a consumption value. Examples include Electric Meters, GPM Meters, BTU Meters, Gas Meters, Etc.
2. Totalizing Devices - This is the device that will collect and store the totalized value collected from the Metering Device. In many cases the totalizing function is part of the Metering Device. Examples include Kele Electric Meters that store the kWh in non-volatile memory or OPTO22 devices that receive a Rate or Pulse input from a Metering Device and store a totalized value in non-volatile memory.
3. Device Level Communications - This is the device that will provide fieldbus communication to the totalizing device. There must be a way for a PC to communicate with a Totalizing device to collect the totalized value. In some cases the ability to communicate is a function of the Totalizing Device. Examples include OPTO22 SNAP Ethernet Brains that can both totalize and communicate via Modbus TCP. Kele Meters can have a BACnet card installed inside the meter to facilitate communication of the totalized value (among other parameters such a line to line voltages).
4. IO Server or Communications Driver - This is software that can read data from the field bus and make it available to other applications running within an operating system such as a Human Machine Interface (HMI).
5. Logging - This is middleware that can collect data from an application like an HMI or IO Server and write it to a database or flat file. Logging is often a function of storage. Samples of totalized data (like kWh or Gallons) and rate data (like Watts or GPM) must be time stamped and stored by logging software if the data will be used to create reports or charts. Expensive examples include SmartStruxure Report Server, and Wonderware Historian. Inexpensive examples include the Enterprise Server's logging capability and Control Suite's InTouch Trending Engine.
6. Storage - This is software that can write data to physical media and provides a mechanism for retrieval. An Expensive example would be Microsoft SQL Server. An inexpensive example would be the Extended Trend Log in a SmartStruxure Enterprise Server or the LGH files created by the InTouch Trending Engine.
9. Display and Dashboard