Title: Replacing Hardware With Software Analysis and simulation of existing hardware using Discrete Event System Specification.
1Replacing Hardware With Software Analysis and
simulation of existing hardware using Discrete
Event System Specification.
- By Philip Felber
- Aman Gupta
- Imaduddin Mohammed
- Kwadwo Adomako
- November 27, 2001
- Prepared for Dr. James Stine
- ECE 587 Hardware / Software CoDesign
- Illinois Institute of Technology
2Replacing Hardware With Software
3Replacing Hardware With Software
- Large apartment buildings built in the seventies
(before embedded computers) were equipped with
custom electronic security and control systems.
4Replacing Hardware With Software
- Apartment Security Panel
- Security
- Package Notification
- Fire Alarm
- Emergency
Security On
Package
(loudspeaker)
OFF
ON
Security Key Switch
5Replacing Hardware With Software
- System components
- Apartment security panels (in each unit)
- Central communications controller
- Alarm readout at front desk
- Keypad terminal at receiving room
6Replacing Hardware With Software
- Today its increasingly hard to find both repair
parts and technicians who understand this
antiquated hardware.
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- With DEVS as a framework, this study analyzes
and simulates a legacy security system and
assesses opportunities to replace certain
hardware components with software.
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9Replacing Hardware With Software
- The Discrete Event System Specification (DEVS)
environment is a system based simulation tool
that provides expandability with modular and
hierarchical features and flexibility. - DEVS framework consists of
- real system
- model
- simulator
- experimental frame
-
- These are related by two relations
- modeling relation
- simulation relation
10Replacing Hardware With Software
Experimental frame
Source System
Simulator
Behavior database
Simulation Relation
Modeling Relation
Model
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- In the DEVS formalism, there are two models to be
specified - Atomic Model from which larger models are built
- Coupled Model
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- Atomic Model contains
- Set of input ports
- Set of output ports
- Set of state variables and parameters
- Internal transition
- External transition
- Output function
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- Coupled Model must contain
- Set of components
- Set of input ports
- Set of output ports
- Coupling specifications
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- Imaduddin Specific analysis
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Input Events
Output Events
States
- Identify the Input Events.
Key Position
- Identify Internal States.
Door Position
Intrusion
Emergency
Fire
Package
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- Hierarchical Model of the System
Coupled Model
Central Communication Control
Alarms to front desk
Coupled Model
Apartment Panel
Package Notification from Receiving room
Atomic Model
Security Alarm
Emergency Alarm
Fire Alarm
Atomic Model
Key
Door
Atomic Model
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Start
Initialize States
Wait For Input Event
NO
Input Event Occurs
YES
Process the request Give output
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Input Event
Output Event
Central Communication Control Module
PkgReceive Module
AptPanel Module
Package Arrival
Set package Light ON
State----------------? Pkg Before Input Event
?NO After Input Event -?Yes
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20Replacing Hardware With Software
- What we have accomplished
- Analysis of the system with DEVS formalism.
- Choose which components we can replace with
software. - Simulate the system.
- The DEVS simulation may develop into the actual
production program.
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- Advantages of our Design
- Our design makes the system faster.
- It provides room for further additions to the
system. - It is easier to maintain.
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- Whats yet to be done?
- Complete the simulation program of the system in
java. - Complete documentation of the project.
23Replacing Hardware With Software Summary
- Some parts of legacy hardware systems are
candidates for emulation by software running on
general purpose microprocessors. - DEVS may be a useful tool for analysis and
simulation. - The DEVS simulation may develop into the actual
production program.
24Replacing Hardware With Software Where To Get
More Information
- Zeigler, Praehofer, and Kim Theory of Modeling
and Simulation Integrating Discrete Event and
Continuous Complex Dynamic Systems, Academic
Press, 2000. - Search the NET for DEVS.
- www.ece.iit.edu/pfelber/devs/ibms/