Configuring Systems From Components: The EMS Approach

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Configuring Systems From ComponentsThe EMS
Approach
ACAT03

• Jerzy M. Nogiec
• Fermilab

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Outline
EMS Goal . EMS Framework
. Application Development with EMS. EMS
Special Features .. Wrap-Up ...
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Goal
The goal of the EMS project is to design,
implement, and deploy a system that is extensible
and flexible, and therefore suitable for RD
environments. It should satisfy ever changing
requirements, support agile development of
applications, and promote reuse.
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EMS

• EMS is a component-based framework for
  building test and data analysis systems.
• EMS is developed in Java to guarantee
  portability and facilitate the use of
  object-oriented development technologies.

Framework the skeleton of an application that
can be customized and reused Component an
independently released software module suitable
for composition (together with other components)
into multiple applications
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Architecture
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Component Interfaces
Components have properties and state. Typical
components input, process, and output data. Their
behavior depends on their state and property
values. Components can be forced to perform
certain actions by sending control events to
them. Components also output debug and exception
information.
control

• properties
• state
• error status

data
data
exception
debug
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Component Connectivity

• There are several categories of data processing
  components
• Data sinks
• Data sources
• Data filters/processors
• Data splitters
• Data mergers

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Application Development
Application
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Components

• Core components
• Application monitoring
• Scripting
• Event processing
• Data Presentation
• Graphing components
• Display components
• Control Input
• Data Processing
• Data Input/Output
• File I/O
• Database access
• URL access
• DAQ

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GUI Components
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Component User Documentation

• EMS Help Viewer assists users in selecting and
  configuring components.
• EMS Help Composer assists developers in
  producing the user-focused documentation

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Connecting Components

• EMS provides for independent wiring of
  components for property, data, exception,
  control, and debug events.
• EMS supports unicast, multicast, and broadcast
  patterns.
• Source routing (dynamic, run-time) routing
  tables (static, configuration-time).

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EMS XML Dialect
ltconfiguration version"0.1" title"Display Test
XML"gt lt!-- Component definitions --gt
ltcomponent id"Producer class"ems.core.componen
ts.SimpleDataGenerator"gt ltproperty
name"title" value"Data Generator Component"/gt
lt/componentgt ltcomponent id"Chart"
class"ems.measurement.chart.ChartDataDisplay"gt
ltproperty name"XPosition"
value"0"/gt ltproperty
name"YPosition" value"200"/gt
ltproperty name"title" value"Plot Display"/gt
lt/componentgt lt!-- Routing information
--gt ltroute type"Data"
origin"Producer" destination"Chart" /gt
lt!-- Control signals --gt ltcontrol
signal"init" destination"!"/gt ltcontrol
signal"start" destination"!"/gt lt/configurationgt
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Tailoring

• Tailoring run-time modification of behavior of
  components.
• Tailoring could be used to refine configurations
  at run-time.
• The PropertySheet component allows for tailoring
  and controlling other components.

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Scripting

• Scripting allows for automation of processing and
  for quick construction of new tests or data
  processing logic.
• The script interpreter is responsible for
  interpreting Python scripts.
• The script control panel allows for selecting,
  running, and monitoring a script.

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Monitoring Application

• The communication on the bus can be selectively
  monitored using the event monitor component.
• Memory usage can be monitored using the memory
  monitor component.
• Timing of components can be monitored.
• Debugging and/or exception information can be
  routed to a separate display or I/O component.

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EMS Features

• Component technology to allow for reuse
• Architecture that supports extensibility
• Configurable applications
• Tailoring of applications at run-time
• Scripting to rapidly develop or modify
  applications
• Integrated application monitoring, debugging, and
  exception handling
• Highly-configurable components
• Universal components that accept various
  collections of data items

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WrapUp

• EMS is a flexible Java-based framework.
• EMS allows for high level of reuse.
• EMS features allow for agile development of new
  applications and easy adaptation of existing
  applications to changing requirements.

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Resources

• EMS web site
• http//sdsg.fnal.gov/emsweb

EMS on-line documentation http//wwwtsmtf.fnal
.gov/ems_javadoc2.X