Arcom changing the face of AMR: Arcom enables a "wireless" HART EXTENDED AMR network for delivering data directly to the business enterprise

Pipeline & Gas Journal, July, 2002

Arcom recently designed and delivered an innovative automation project involving multiple "wireless" messaging links, utilizing the power and adaptability of HART communication technology in conjunction with the first use of a fully scaleable ERP integration message broker for automatic meter reading (AMR). HART provided the communication tool needed to create an extended meter reading network via spread spectrum radio and satellite communication. Arcom provided the link between the broker and meter with the Director Series Network Gateway.

A major Midwest gas pipeline company planned to replace paper chart recorders on their natural gas pipeline with an AMR system. The AMR system would have to be capable of acquiring data from devices within a radius of up to 80 miles, making available field data from locations throughout the Midwest to a central host, and integrating the data with an existing measurement system.

To meet the challenge, the pipeline company's engineers chose Arcom's Director. The Director is a multi-protocol based network gateway/multiplexor from Arcom Control Systems and a HART enabled multivariable flow transmitter that provides flow measurement and data logging capabilities.

Competition in the energy sector requires multiple applications utilizing real-time data for optimization, control, spot-market selling, CIS and maintenance just to name a few. The company chose an Arcom technique of revolutionizing the way SCADA data is sent to the business enterprise. The technique is a lightweight publish/subscribe data queuing topology that has been widely prominent in the financial industries.

The Pub/Sub topology is a protocol, device and application independent system with robust tools and transformation capabilities breaking the chains that have been locking data from islands of operation. The monopoly placed by vender specific and protocol dependent devices and applications hold companies captive due to proprietary nature that eliminates the use of new technology, cost-saving techniques and optimization. The AMR system uses spread spectrum radio and satellite communication to extend the HART network beyond the traditional 10,000-foot (3,000-meter) distance limitation. Spread spectrum radios provide the wireless link between the Director and the HART instruments.

At each remote site the radio connects to the field devices using a serial HART interface. This transmits the RS-232 HART signal from the radio onto the local current loop to a single or multi-dropped HART network. Because up to 32 devices per radio network were required, the HART "poll by tag" feature was implemented to allow more than the traditional 15 devices.

By implementing the HART-based AMR system, the pipeline company was able to realize cost savings in several ways. The paper chart recorders previously had to be collected and tabulated manually for each monthly billing. Now, this is done automatically with ongoing savings estimated at $1.25 million per year. The wireless communication avoids very costly cable runs to each HART meter. The multivariable flow transmitter effectively combines a traditional flow meter and three discrete instruments into a single instrument, yielding hardware cost savings of almost 30% per site. TCP/IP communication allows remote diagnostics and configuration, reducing the need for onsite technical support. Because the HART signal is transferred over the radio link, there is no need for a separate Remote Terminal Unit (RTU) or multiplexer at each meter site. One Director is master to 32 HART meters, allowing data consolidation.

The Director polls the HART meters and acquires the different data sets (alarms, instantaneous data, 15 minute archives, etc). It publishes the message/data the message broker, which provides through subscription the connectivity and transformation of the data to the multiple applications in the business enterprise. The applications receive data in their standard format from the message broker eliminating proprietary problems created from the device manufacturer's protocol and form of data. Thus, any current or future application and new device can be added without a migration and proprietary nightmare. This is ideal permitting the company to spend most of its time increasing productivity through business logic and enabling technologies not integration.

Global industry growth continues to present an ever-increasing challenge to provide strong networking and interoperability communications solutions. Arcom Control Systems, Inc is meeting the critical challenges in the energy market by continually investing and creating beneficial and cost-saving new technologies.