RPM is the concept of communicating critical system data to the appropriate decision-makers, whether it be an embedded, automated controller or a senior executive, in real-time. The results are promising -- the ability to quickly adapt a process or plant to a significant, recent change in environment, customer demands, or supplier stock. And in a world where just-in-time (JIT) manufacturing is becoming more attractive (e.g. Dell), the ability to have a real-time dashboard of the current process is not a nicety, it''s a requirement.
Given the distributed nature of most process automation systems, multiple embedded processing nodes with unique development tools and communication capabilities, implementing an effective system for machine-to-machine communication is difficult. However, the nature of an RPM system demands a form of distributed intelligence -- enabling the individual, intelligent nodes of the system to communicate and make decisions while also transferring critical information up the chain to the rest of the enterprise.
Ideally, every device on a plant floor would feature an identical architecture -- same embedded processor, same software development chain, same communication protocol. In reality, existing plant floors are a conglomeration of acquisition and control hardware, each with unique development tools, each "talking" on a different bus. The heterogeneous nature of today''s manufacturing floor dictates two essential characteristics of the RPM system -- open communications capabilities and flexible software architecture. (The National Instruments PAC Platform, shown here, includes: Compact Vision System, Compact FieldPoint, CompactRIO and PXI. All devices are programmable with NI LabVIEW software.)
Openness and flexibility are the primary value-adds of COTS technology. Many National Instrument customers who are building or plugging into existing process automation systems are looking to Ethernet for the communications protocol, as it is a dominant standard for high-speed, reliable data transfer. The growing area of programmable automation controllers (PACs), including NI Compact FieldPoint or CompactRIO, is moving strongly toward Ethernet-focused communication. However, legacy systems likely leverage a variety of more traditional industrial protocols such as Modbus, FieldBus, DeviceNet, and others. The good news is that a growing number of communication gateways are available, bridging between Ethernet and other protocols, facilitating the expansion and updating of these legacy systems.
Once the communication gap has been solved, the key to distributed intelligence and the resulting RPM capabilities is software. Many NI customers are using the LabVIEW graphical development environment for their applications. Their primary care-abouts are:
- Advanced analysis capabilities for deriving important information from data
- Broad communications protocol support, including Ethernet
- Overall system software management capabilities -- visibility into what is going on at each individual node in the system
- Enterprise connectivity, including database logging, web interfaces, HMIs, etc.
- Multiple target capabilities -- a single development tool that supports a variety of hardware architectures, including real-time systems, FPGA-based systems, and even embedded processors.
Overall, the concept of RPM is sound and it is my opinion that these concepts are going to see further adoption in the general industrial automation market. The diverse hardware and communication mix of today''s plant floors presents a significant challenge that is addressable through a combination of open, Ethernet-based communication and flexible software.