New Model Needed for Oil, Gas Data Communications

Implementing a Distributed Communications Architecture

A company could implement a Distributed Communications Architecture in many ways, but Paine and Treat point to the OPC Unified Architecture (UA) standard, a multi-purpose set of services that a data collector – or OPC server – provides to application that is ready to consume information.

OPC UA is the interoperability standard for the secure and reliable exchange of data in the industrial automation space and in other industries. According to the OPC Foundation, which oversees development and maintenance of the standard, OPC is a series of specifications developed by industry vendors, end-users and software developers, which define the interface between clients and servers, as well as servers and servers, including real-time data access, monitoring of alarms and events, access to historical data and other applications.

When it was first released in 1996, the standard was intended to abstract programmable logic controller (PLC) specific protocols into a standardized interface, allowing human machine interface/supervisory control and data acquisition (HMI/SCADA) systems to interface with a “middle-man” who would convert generic-OPC read/write requests into device specific requests and vice versa, according to the OPC Foundation.

OPC UA specifications have been developed to address the challenges of security and data modelling that have accompanied the introduction of service-oriented architectures in manufacturing systems.

“With all these automation companies like Siemens and General Electric having native protocols with all of the different SCADA and HMI applications, you can’t write all these different protocol drivers to communicate with different types of devices,” said Steve Sponseller, product manager for business development with Kepware, in an interview with Rigzone. “Why not come out with a standard so applications on top only have to support the OPC standard?”

Kepware is seeking to address this issue with its KEPServerEX, which can be connected to several types of devices on a rig or wellsite through the driver layer. Using different drivers, Kepware pulls data from data bases, other OPC servers, from some HMI systems, and other sources through Kepware’s custom driver. Data is then passed on to connected clients from a rig or piece of equipment into a corporate historian, which might be centrally located at an office. Data is then available for playback when bandwidth is available. When bandwidth is not available due to weather, obstructions, other data going across, data continues to be collected locally and resumes playback to the historian once communications become available again.