Struct SubRequest 

pub struct SubRequest { /* private fields */ }

Represents a collection of sub-requests for Modbus File Record operations.

A single Modbus PDU for FC 0x14 or 0x15 can contain multiple sub-requests, allowing the client to read from or write to different files and records in one transaction.

This struct manages the aggregation of these requests and performs validation to ensure the resulting PDU does not exceed the Modbus protocol limit of 253 bytes.

Implementations

impl SubRequest

pub fn new() -> Self

Creates a new empty SubRequest.

pub fn add_read_sub_request( &mut self, file_number: u16, record_number: u16, record_length: u16, ) -> Result<(), MbusError>

Adds a sub-request for reading a file record.

Arguments

• file_number - The file number.
• record_number - The starting record number.
• record_length - The number of registers to read.

pub fn add_write_sub_request( &mut self, file_number: u16, record_number: u16, record_length: u16, record_data: Vec<u16, MAX_PDU_DATA_LEN>, ) -> Result<(), MbusError>

Adds a sub-request for writing a file record.

Arguments

• file_number - The file number.
• record_number - The starting record number.
• record_length - The number of registers to write.
• record_data - The data to write.

pub fn byte_count(&self) -> usize

Calculates the total byte count for the sub-requests payload.

pub fn clear_all(&mut self)

Clears all sub-requests.

Trait Implementations

impl Clone for SubRequest

fn clone(&self) -> SubRequest

Returns a duplicate of the value.

fn clone_from(&mut self, source: &Self)

Performs copy-assignment from source.

impl Debug for SubRequest

fn fmt(&self, f: &mut Formatter<'_>) -> Result

Formats the value using the given formatter.

impl Default for SubRequest

fn default() -> SubRequest

Returns the “default value” for a type.

impl PduDataBytes for SubRequest

fn to_sub_req_pdu_bytes(&self) -> Result<Vec<u8, MAX_PDU_DATA_LEN>, MbusError>

Converts the sub-request parameters into a byte vector for the PDU.