Struct BlockData 

pub struct BlockData {
    pub block_type: u16,
    pub block_number: u16,
    pub format: u16,
    pub total_length: u32,
    pub flags: u16,
    pub crc1: u16,
    pub crc2: u16,
    pub payload: Vec<u8>,
}

A raw PLC block in the Siemens Diagra upload/download format.

The wire format starts with a 20-byte header:

[blk_type:2][blk_number:2][format:2][length:4][flags:2][crc1:2][crc2:2][??:4]

followed by the MC7 code / data payload, and optionally trailer strings.

Fields

block_type: u16

Block type identifier (see BlockType discriminants).

block_number: u16

Block number.

format: u16

Block format/encoding version.

total_length: u32

Total block length (including header).

flags: u16

Block flags.

crc1: u16

First CRC value.

crc2: u16

Second CRC value.

payload: Vec<u8>

Raw MC7 code / data payload (everything after the 20-byte header).

Implementations

impl BlockData

pub fn from_bytes(data: &[u8]) -> Option<Self>

Parse raw uploaded bytes into a BlockData.

pub fn to_bytes(&self) -> Vec<u8>

Serialize back to wire bytes (for download).

pub fn new_db(db_number: u16, size_bytes: u16) -> Self

Build a minimal empty DB block ready for download.

Creates a Diagra-format block with the S7 DB header structure. size_bytes is the desired DB size in bytes (must be even).

pub fn crc32(&self) -> u32

Compute a CRC-32 checksum of the serialized block bytes.

Suitable for comparing a locally stored block against one uploaded from the PLC: local.crc32() == plc_block.crc32().

pub fn set_attributes(&mut self, attrs: &BlockAttributes)

Apply BlockAttributes to this block in-place.

The S7 block footer is at payload[payload.len()-48..] (when payload is large enough). Author/Family/Name each occupy 8 bytes at fixed offsets within the footer.

pub fn type_name(&self) -> &'static str

Return the human-readable block type name.

Trait Implementations

impl Clone for BlockData

fn clone(&self) -> BlockData

Returns a duplicate of the value.

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

Performs copy-assignment from source.

impl Debug for BlockData

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

Formats the value using the given formatter.