File syn_mbus.c¶

FileList > proto > syn_mbus.c

M-Bus (Meter-Bus) master/slave protocol framing implementation.

#include "../util/syn_assert.h"
#include "syn_mbus.h"
#include <string.h>

Public Types¶

Type	Name
enum	syn__mbus_8c_1adf764cbdea00d65edcd07bb9953ad2b7

Public Functions¶

Type	Name
uint8_t	syn_mbus_calc_checksum (const uint8_t * data, size_t len) Calculate M-Bus 8-bit checksum (modulo-256 sum over specified buffer).
SYN_Status	syn_mbus_decode_frame (const uint8_t * buf, size_t len, SYN_MBUS_Frame * frame) Decode a raw M-Bus byte buffer into a frame structure.
void	syn_mbus_decoder_feed (SYN_MBUS_Decoder * dec, uint8_t byte) Feed a single byte to the streaming M-Bus decoder.
void	syn_mbus_decoder_init (SYN_MBUS_Decoder * dec, SYN_MBUS_FrameCallback callback, void * ctx) Initialize an M-Bus streaming state machine decoder.
void	syn_mbus_decoder_reset (SYN_MBUS_Decoder * dec) Reset the streaming decoder state.
SYN_Status	syn_mbus_encode_ack (uint8_t * buf, size_t cap, size_t * out_len) Encode a Single Character ACK frame (0xE5).
SYN_Status	syn_mbus_encode_control (uint8_t c_field, uint8_t a_field, uint8_t ci_field, uint8_t * buf, size_t cap, size_t * out_len) Encode a Control Frame (9 bytes: 0x68 \| 0x03 \| 0x03 \| 0x68 \| C \| A \| CI \| Checksum \| 0x16).
SYN_Status	syn_mbus_encode_long (uint8_t c_field, uint8_t a_field, uint8_t ci_field, const uint8_t * payload, uint8_t payload_len, uint8_t * buf, size_t cap, size_t * out_len) Encode a Long Frame (0x68 \| L \| L \| 0x68 \| C \| A \| CI \| Payload... \| Checksum \| 0x16).
SYN_Status	syn_mbus_encode_short (uint8_t c_field, uint8_t a_field, uint8_t * buf, size_t cap, size_t * out_len) Encode a Short Frame (5 bytes: 0x10 \| C \| A \| Checksum \| 0x16).

Public Types Documentation¶

enum syn__mbus_8c_1adf764cbdea00d65edcd07bb9953ad2b7¶

enum syn__mbus_8c_1adf764cbdea00d65edcd07bb9953ad2b7 {
    STATE_IDLE = 0,
    STATE_SHORT_C,
    STATE_SHORT_A,
    STATE_SHORT_CHK,
    STATE_SHORT_STOP,
    STATE_LONG_L1,
    STATE_LONG_L2,
    STATE_LONG_SOF2,
    STATE_LONG_BODY
};

Public Functions Documentation¶

function syn_mbus_calc_checksum¶

Calculate M-Bus 8-bit checksum (modulo-256 sum over specified buffer).

uint8_t syn_mbus_calc_checksum (
    const uint8_t * data,
    size_t len
)

Parameters:

data Pointer to buffer.
len Length of data in bytes.

Returns:

Calculated checksum byte.

function syn_mbus_decode_frame¶

Decode a raw M-Bus byte buffer into a frame structure.

SYN_Status syn_mbus_decode_frame (
    const uint8_t * buf,
    size_t len,
    SYN_MBUS_Frame * frame
)

Parameters:

buf Input byte buffer containing a complete M-Bus frame.
len Buffer length in bytes.
frame Destination frame structure.

Returns:

SYN_OK on success, SYN_ERR_INVALID_CHECKSUM on checksum failure, or error status.

function syn_mbus_decoder_feed¶

Feed a single byte to the streaming M-Bus decoder.

void syn_mbus_decoder_feed (
    SYN_MBUS_Decoder * dec,
    uint8_t byte
)

Parameters:

dec Decoder instance.
byte Byte received from UART/RS232/transceiver.

function syn_mbus_decoder_init¶

Initialize an M-Bus streaming state machine decoder.

void syn_mbus_decoder_init (
    SYN_MBUS_Decoder * dec,
    SYN_MBUS_FrameCallback callback,
    void * ctx
)

Parameters:

dec Decoder instance.
callback Callback called upon successful frame completion.
ctx User context passed to callback.

function syn_mbus_decoder_reset¶

Reset the streaming decoder state.

void syn_mbus_decoder_reset (
    SYN_MBUS_Decoder * dec
)

Parameters:

dec Decoder instance.

function syn_mbus_encode_ack¶

Encode a Single Character ACK frame (0xE5).

SYN_Status syn_mbus_encode_ack (
    uint8_t * buf,
    size_t cap,
    size_t * out_len
)

Parameters:

buf Output buffer.
cap Buffer capacity (must be >= 1).
out_len Receives total bytes written (1).

Returns:

SYN_OK on success, or error status.

function syn_mbus_encode_control¶

Encode a Control Frame (9 bytes: 0x68 | 0x03 | 0x03 | 0x68 | C | A | CI | Checksum | 0x16).

SYN_Status syn_mbus_encode_control (
    uint8_t c_field,
    uint8_t a_field,
    uint8_t ci_field,
    uint8_t * buf,
    size_t cap,
    size_t * out_len
)

Parameters:

c_field Control field byte.
a_field Address field byte.
ci_field Control Information field byte.
buf Output buffer.
cap Buffer capacity (must be >= 9).
out_len Receives total bytes written (9).

Returns:

SYN_OK on success, or error status.

function syn_mbus_encode_long¶

Encode a Long Frame (0x68 | L | L | 0x68 | C | A | CI | Payload... | Checksum | 0x16).

SYN_Status syn_mbus_encode_long (
    uint8_t c_field,
    uint8_t a_field,
    uint8_t ci_field,
    const uint8_t * payload,
    uint8_t payload_len,
    uint8_t * buf,
    size_t cap,
    size_t * out_len
)

Parameters:

c_field Control field byte.
a_field Address field byte.
ci_field Control Information field byte.
payload Pointer to payload data buffer.
payload_len Payload length (max 252 bytes).
buf Output buffer.
cap Buffer capacity (must be >= payload_len + 9).
out_len Receives total bytes written.

Returns:

SYN_OK on success, or error status.

function syn_mbus_encode_short¶

Encode a Short Frame (5 bytes: 0x10 | C | A | Checksum | 0x16).

SYN_Status syn_mbus_encode_short (
    uint8_t c_field,
    uint8_t a_field,
    uint8_t * buf,
    size_t cap,
    size_t * out_len
)

Parameters:

c_field Control field byte.
a_field Address field byte.
buf Output buffer.
cap Buffer capacity (must be >= 5).
out_len Receives total bytes written (5).

Returns:

SYN_OK on success, or error status.

The documentation for this class was generated from the following file src/syntropic/proto/syn_mbus.c