WebLogic RFID Edge Server Architecture

ALE data processing engine—Receives, processes, writes, and filters RFID tag data according to Event Cycle Specifications (ECSpecs), as defined by the EPCglobal ALE specification.

An ECSpec describes a particular combination of readers, filters, and reporting options, defined by an application. ECSpecs may be defined programmatically using the ALE API (via the SOAP listener), or using command-line tools provided with WebLogic RFID Edge Server.

Monitoring and management agent—Monitors and manages the health and functioning of readers and Edge Server software remotely through the RFID Edge Server Administration Console.

The management agent also provides real-time telemetry, including the number of tags read, the read cycle time, and when the read cycles occurred. Real-time telemetry is useful in diagnosing the overall health of the RF environment in which readers operate.

Local workflows—Out of the box workflows for observing case and pallet count, associating cases with pallets, and determining the direction of product movement, that are configurable through the RFID Edge Server Administration Console.

Administration Console

The Administration Console is software typically deployed at a centralized enterprise site, where operations staff can use it to:

Configure and monitor the activities of multiple Edge Servers and readers
Add, remove, and configure readers and composite readers
View and manage ECSpec data objects and their subscribers
Configure and deploy workflows
View real-time Edge Server and RFID device telemetry data

RFID Readers

You need one or more RFID readers to use RFID Edge Server. RFID Edge Server supports the most widely used RFID readers, which are listed in the RFID Readers Reference.

If you do not have a reader, you can use the reader simulator software provided with WebLogic RFID Edge Server. Out of the box, it runs on any workstation and simulates a ThingMagic Mercury4 reader; with minor editing it can simulate a Printronix reader. The reader simulator is useful for software evaluation, application development, and debugging. See Using the Reader Simulator.

Functional Overview

By gathering unique identification data at many detection locations, the RFID Edge Server provides item-level detection for literally billions of items. To handle this process effectively, the RFID Edge Server must:

Minimize the amount of data communicated
Make communications as efficient as possible
Make the system robust to communications outages and configuration changes

Data Processing

All access to data from RFID readers is made using the ALE engine of the WebLogic RFID Edge server. The RFID Edge Server uses single-layer filtering at a low level in the architecture. The filtering is generic enough to support different readers and different application needs, and it returns information in a standardized format. The standardized interface for client applications is the ALE API. The ALE API allows applications to specify exactly the type of information required from a raw stream of RFID data, such as:

Locations for reading tag data (where a location maps to one or more RFID readers or antennas)
Time interval for accumulating data (absolute time or a time interval triggered by external events, such as motion detectors)
How to filter the data
How to group the results
Whether to report all the currently visible tags or only the additions and deletions
Whether to report actual tag values or just a count of the tags that were read

Applications all send requests to the filtering layer and the filtering layer subsequently provides reports back to the applications.

Reader-level events filtering through the ALE processing engine

Reduces the volume of data to applications
Elevates the level of abstraction for application writers
Insulates applications from device details
Shares data among multiple applications

Device management through the RFID Edge Server Administration Console

Manages reader configuration such as setup, reboot, and individual requirements of each reader model
Monitors reader health, for example, determines whether no tag reads means that no goods are received or that the reader is broken
Provides real-time monitoring of radio (RF) environment health, that is, helps determine whether data is useful

Local workflows turn low-level technical events into meaningful business events

Provides integration of readers and user feedback devices (stack lights, LEDs, and such)
Workflow modules subscribe to ECReports and add the required business-oriented information, such as business location ID and business process step ID
The result of a workflow process could be an EPCIS document, or some other XML payload, that will then be transported to upstream enterprise IT subsystems using JMS (topic or queue) or HTTP

Connectivity

Key functionality of WebLogic RFID Edge Server includes establishing and maintaining network connections to RFID devices, insuring that they are properly configured, retrying connections in the event of failure, and exchanging device read and write events with the ALE engine. For devices with built-in Ethernet capability, WebLogic RFID Edge Server interfaces with the network using the device's own proprietary protocol (every device manufacturer defines its own protocol, sometimes a different protocol for different models within the same product family). For devices having only a serial connection (such as, RS-232, RS-485), a serial-to-Ethernet converter is used.

WebLogic RFID Edge Server also allows you to receive information about other RFID devices and control them by communicating with a programmable logic controller (PLC), a specialized industrial computer used for automation of real-world processes.

Developer Resources

Applications interact with the Edge Server through the ALE API. The ALE interface provides a high-level, declarative way for applications to obtain RFID data, without requiring application programmers to interact directly with RFID readers or perform any low-level real-time processing or scheduling operations. For detailed information about the ALE interface, see Programming with the ALE and ALEPC APIs and the ALE and ALEPC Javadoc.

RFID Resources

EPCglobal—A non-profit organization set up by the Uniform Code Council and EAN International, the two organizations that maintain bar code standards, to commercialize EPC technology. EPCglobal has chapters in various countries and regions. It is commercializing the technology originally developed by the Auto-ID Center.

EPCglobal Tag Data Standards—This document is available on the EPCglobal Web site at http://www.epcglobalinc.org.

International Organization for Standardization (ISO)—A non-governmental organization of national standards institutes in 146 countries. Each member country has one representative, and the organization maintains a Central Secretariat in Geneva, Switzerland, that coordinates the system.
ISO Standards—ISO has developed RFID standards for automatic identification and item management. For a comprehensive overview of all ISO standards related to RFID, see Radio Frequency Identification (RFID) Identification (RFID) - ISO & ISO/IEC Standards.

Product Overview