Lesson-1-Block-Diagrams-and-Flowcharts

Block Diagrams and Flowcharts

Prepared by: Dr. Monaliza S. Jimenez

Block Diagrams

• Definition: A block diagram represents a system where the main parts or functions are depicted as blocks connected by lines that show their relationships.

• Purpose: Provides a quick, high-level overview of a system, identifying points of interest or potential issues without detailing every component (e.g., wires or switches).

• Focus: Concentrates on input and output, adhering to the "black box" principle where internal workings are not the primary concern.

Example Block Diagram

• Consists of various components:

  • Suppliers

  • Bargaining Power of Suppliers

  • Threat of Substitute Products or Services

  • Potential Entrants

  • Industry Competitors

  • Rivalry Among Existing Firms

  • Bargaining Power of Buyers

Components in Block Diagrams

• Clock Pulse Generator (Schmitt Trigger Quad Two-Input NAND Gate)

• Random Number Generator IC4033: Functions as a Decade Counter/Decoder/7-Segment LED Display Driver.

• Control Pulse Generator IC4093: Another variant of Schmitt Trigger Quad Two-Input NAND Gate.

• Various Controllers and Counters (e.g., IC4017, IC4027, etc.) related to score counting and sound output.

Uses and Importance of Block Diagrams

• General Uses: Extensively used in hardware design, electronic design, software design, and process flow diagrams.

• Applications:

  • Hardware and software developers use block diagrams to describe workflows and processes.

  • Electricians represent complex systems, such as mechatronic systems in the trucking industry.

  • Facilitate a clear understanding of complicated algorithms or communication flows.

Block Diagrams in Software Design

• Efficiently represent overall functionings of computer systems.

• Display necessary processes from inputs leading to desired outputs.

Block Diagrams in Electrical Engineering

• Example: Instrumentation channel diagram to measure neutron flux, with blocks indicating stages of signal development.

Block Diagrams in Process Control

• Displays essential elements of a feedback control system:

  • Reference Input (Setpoint)

  • Actuating Signal

  • Feedback Signal and Elements

  • Controlled Variable (Output)

Symbols Used in Block Diagrams

• Basic geometric shapes: boxes and circles.

• Blocks represent functions, while arrowed lines indicate signal flow.

Components and Elements

• Basic Elements: Block, summing point, and take-off point.

• Summing Point: Circle marked with X, takes multiple inputs and produces an output based on signs indicating summation or subtraction.

• Take-off Point: Point that allows input signal to branch into multiple paths.

Tips for Creating Block Diagrams

1. Identify the system and its components, inputs, and outputs.

2. Create a labeled diagram with symbols corresponding to system components and arrows for flow.

3. Indicate inputs and outputs clearly.

4. Verify diagram accuracy with stakeholders.

Flowcharts

• Definition: A type of diagram that represents algorithms, workflows, or processes.

• Structure: Shows steps as boxes of various types, connected by arrows indicating order.

• Purpose: Illustrates a solution to a specific problem.

Flowchart Symbols

• Terminator: Indicates start/end of flow.

• Process: Represents processing functions.

• Decision: Shows decision points, typically in diamond shape.

• Data: Represents any type of data within the flow.

Types of Flowcharts

• Basic Flowchart: Simplistic diagram showing step-by-step execution of algorithms; easy for comprehension.

• Business Process Modeling Diagram (BPMN): Visual representation of business processes in workflow.

• Cross-Functional Flowchart: Displays detailed algorithm execution, highlighting participant interactions and roles, often using swim lanes.

• Data Flow Diagram (DFD): Graphically represents information systems' workings, interactions with external data sources.

• Event-driven Process Chain (EPC) Diagram: Flowchart modeling business processes using events and functions, with logical operators for branching.

• Integrated DEFinition Flowchart (IDEF): Functional modeling method describing complex system processes.

• Influence Diagram: Alternative to decision trees depicting relationships in decision-making.

• Swimlane Flowchart: Documents business processes divided among workers and departments for clarity.

• Process Flow Diagram (PFD): High-level depiction of industrial processes.

• Specification and Description Language Diagram (SDL): A specification language used for real-time systems.

• Value Stream Mapping: Analyzes and designs systems to enhance product/service delivery.

• Workflow Diagram: Graphically outlines information flows and relationships in processing stages.

Conclusion

• Understanding block diagrams and flowcharts is crucial in various fields, including engineering, software development, and process control. They serve as fundamental tools for visualizing systems and workflows.