firmware-base/docs-c/modbus/ModbusTypes.md

title	description	keywords
ModbusTypes Reference	Comprehensive reference for the ModbusTypes component used in Modbus RS-485 industrial applications	modbus industrial esp32 rs485 communication

ModbusTypes

Path: src/modbus/ModbusTypes.h

Revision History: Initial documentation

A collection of enumerations, structures, and classes that define the foundational types used by the Modbus implementation. This component provides the core data types and interfaces for working with Modbus communication in industrial applications.

REQUIREMENTS

• ESP32 microcontroller
• Platform.io development environment
• C++17 compatible compiler

PROVIDES

• Enumerations:

  • E_FN_CODE: Modbus function codes
  • E_MB_OpType: Modbus operation types
  • E_MB_OpStatus: Operation status
  • MB_Error: Error codes
  • E_FilterType: Filter types for operation filtering
  • E_ModbusAccess: Access types (from config-modbus.h)

• Structures:

  • MB_Registers: Register definition structure
  • ModbusBlockView: Non-owning view of register blocks
  • MB_UpdateData: RTU update data
  • ModbusOperation: Modbus operation structure
  • ModbusValueEntry: Register or coil value entry
  • SlaveData: Modbus slave data
  • ModbusReadBlock: Mandatory read block definition

• Classes:

  • ModbusOperationFilter: Base class for operation filters
  • DuplicateOperationFilter: Filter to remove duplicate operations
  • RateLimitFilter: Filter to limit operation rates
  • PriorityFilter: Filter for prioritizing operations
  • OperationLifecycleFilter: Filter for managing operation lifecycle
  • RegisterState: Class for register state management
  • RTU_Base: Base class for RTU devices

• Callback Types:

  • ResponseCallback: Callback for slave responses
  • OnRegisterChangeCallback: Callback for register changes
  • OnWriteCallback: Callback for write operations
  • OnErrorCallback: Callback for error handling
  • OperationExistsCallback: Callback for checking if operation exists

FEATURES

• Comprehensive Modbus function code support
• Error handling with detailed error codes
• Operation filtering system for queue management
• Register state management
• Device state management through RTU_Base
• Support for mandatory read blocks
• Priority-based operation scheduling
• Callback systems for events

DEPENDENCIES

• Arduino.h
• ArduinoLog.h
• Component.h
• Vector.h
• enums.h
• macros.h
• constants.h
• config-modbus.h

graph TD
    ModbusTypes --> ArduinoLog
    ModbusTypes --> Component
    ModbusTypes --> Vector
    ModbusTypes --> macros
    ModbusTypes --> constants
    ModbusTypes --> config-modbus
    ModbusTypes --> enums
    ModbusRTU --> ModbusTypes
    RTUDevices --> ModbusTypes
    RS485 --> ModbusTypes

BEHAVIOUR

stateDiagram-v2
    [*] --> UNINITIALIZED
    UNINITIALIZED --> INITIALIZING: initialize()
    INITIALIZING --> IDLE: initialization complete
    IDLE --> RUNNING: operations pending
    RUNNING --> IDLE: operations complete
    IDLE --> ERROR: timeout
    RUNNING --> ERROR: timeout
    ERROR --> IDLE: response received

TODOS

PERFORMANCE

• Consider more efficient data structures for queuing operations
• Optimize memory usage in filter chain implementations
• Implement operation batching for improved throughput

SECURITY

• Add validation for input parameters to prevent buffer overflows
• Consider implementing authentication mechanisms for Modbus TCP
• Add checks for unauthorized register access

COMPLIANCE

• Ensure full compliance with Modbus specification
• Review handling of exceptional responses
• Validate operation against industrial standards

RECOMMENDATIONS

• Implement appropriate error handling strategies
• Set appropriate timeouts based on network characteristics
• Use the filter chain to customize operation processing
• Leverage the callback system for event-based programming