This document describes the architectural design of a home security system. It includes entity relationship diagrams, structure charts, data flow diagrams, and process mappings. The system allows users to arm and disarm the security sensors via a control panel. It detects break-ins through connected door and window sensors. Upon a break-in, it sounds an alarm and calls the local police.

1. Architectural Design Workout
From the
‘Problem Description’
to the
‘Call and Return Architecture’
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2. Architectural Design Workout
Problem Description
It is a Home Security System.
It has input buttons to input password, telephone number etc.; it has
also buttons to arm and disarm the system. There are panic buttons
also.
Inputs are taken from the sensors which are connected to doors and
windows to detect any break-ins.
Incase of any break-ins, an alarm goes off and a telephone call is placed
to the local police station.
It has small output LCD display which displays several sensors status
and other command status.
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3. Architectural Design Workout
ERD
Home Owner Arms/Disarms/Configures Alarm
Security
Inputs and outputs Controls Sensors
System
through
Gives inputs and accepts Telephone
Control
Panel Output from
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4. Architectural Design Workout
STD
Input Came
Power Off Get the inputs Process
System Off
Invoke Power-off Seq Input
Power On Wait for
Invoke Inputs Process
Power On Or Sensor Sensor
Diagnostics Events Sensor Events Events
Diag OK Get Status
Wait for Inputs
Unknown State
Display Fault
System On System Fault
Diag Not OK Unknown State
Display Fault Display Fault
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5. Architectural Design Workout
Level 0 DFD ( Context Diagram )
Control
Control Panel
Panel User Commands Messages Display
Buttons And Data
SafeHome On/Off
Software Alarm
Sensor
Status
Sensors Telephone
Number Tones Telephone
Line
Configuration Configuration
Data Data Store
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6. Architectural Design Workout
Level 1 DFD
Command Echo
And Command Display Info
Control Control
Output
Panel 2.0 Panel
1.0 Display
Buttons Display
Process
Messages
User Commands Command
And status
And Data
Sensor Info
Sensor Alarm
Status
3.0 On/Off
Monitor
Sensors Sensors
Telephone
Configuration Telephone Line
Data Number
Configuration Tone
Data Store
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7. Architectural Design Workout
Mapping Level 1 DFD
SafeHome
Main Executive
Process Monitor
Command Sensor
Executive Executive
Display
Messages & Status
Executive
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8. Architectural Design Workout
Level 2 DFD of the ‘Monitor Sensor’ process
3.3
Format Sensor Info
Sensor ID, For
Type, Display
Location
Sensor ID,
Type 3.2
3.1 Alarm Data 3.4
Asses
Sensor Read Generate
Against On/Off
Status Sensors Alarm
Setup Telephone Signal
Number
Configuration
Data 3.5
Dial Telephone
Phone Number Tones
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9. Architectural Design Workout
Mapping ‘Monitor Sensor’ process
Monitor
Sensor
Executive
Sensor Input Transform Sensor Output
Controller Controller Controller
Read Asses
Sensors Against Setup
Dial Generate Format For
Phone Alarm Signal Display
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10. Architectural Design Workout
Consolidating ‘Monitor Sensor’ Process
Monitor
Sensor
Executive
Read Asses Sensor Output
Sensors Against Setup Controller
Dial Generate Format For
Phone Alarm Signal Display
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11. Architectural Design Workout
Level 2 DFD of the ‘Process Command’ process
1.3
Build Configuration
Configuration Data
File
Configure
Command 1.4
Button Type 1.2
Input 1.1 Start/Stop Arm/
Process
Read Disarm
Command
Command System
Arm/Disarm
Password Message
Password
1.5
Configuration Data OK/Not OK
Process
Message
Password
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12. Architectural Design Workout
Mapping ‘Process Command’ process
Process
Command
Executive
Read Process
Command Command
Process Arm/Disarm Build
Password System Configuration
File
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13. Architectural Design Workout
Overall Consolidation
SafeHome
Main Executive
Monitor
Sensor
Process Executive
Command
Executive
Asses Sensor Output
Read Read Against
Process Controller
Command Sensors Setup
Command
Process Arm/Disarm Build
Password System Configuration
File
Dial Generate Format For
Phone Alarm Signal Display
Display
Messages & Status
Executive
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