File syn_bacnet.c¶

FileList > proto > syn_bacnet.c

Zero-malloc, cleanroom BACnet MS/TP & APDU protocol stack implementation.

#include "syn_bacnet.h"
#include <string.h>

Public Functions¶

Type	Name
SYN_Status	syn_bacnet_add_object (SYN_BACnet_Node * node, uint8_t object_type, uint32_t instance_id, float init_value, const char * name) Register an Object in the BACnet Node database.
uint16_t	syn_bacnet_crc16 (const uint8_t * data, size_t len) Calculate BACnet MS/TP Data CRC-16.
uint8_t	syn_bacnet_crc8 (const uint8_t * data, size_t len) Calculate BACnet MS/TP Header CRC-8.
bool	syn_bacnet_mstp_decode_frame (const uint8_t * buf, size_t len, SYN_BACnet_MSTP_Frame * frame) Decode a raw byte buffer into a BACnet MS/TP Frame structure.
size_t	syn_bacnet_mstp_encode_frame (uint8_t frame_type, uint8_t dest_mac, uint8_t src_mac, const uint8_t * payload, uint16_t payload_len, uint8_t * out_buf) Encode a complete BACnet MS/TP Frame.
SYN_Status	syn_bacnet_node_init (SYN_BACnet_Node * node, uint8_t mac_address, uint32_t device_id) Initialize a BACnet MS/TP Node context.
SYN_Status	syn_bacnet_node_process (SYN_BACnet_Node * node, const SYN_BACnet_MSTP_Frame * rx_frame, SYN_BACnet_MSTP_Frame * tx_frame, bool * has_tx) Process an incoming BACnet MS/TP frame and generate a response if required.

Public Functions Documentation¶

function syn_bacnet_add_object¶

Register an Object in the BACnet Node database.

SYN_Status syn_bacnet_add_object (
    SYN_BACnet_Node * node,
    uint8_t object_type,
    uint32_t instance_id,
    float init_value,
    const char * name
)

Parameters:

node Node handle.
object_type SYN_BACnet_ObjectType (AI, AO, BI, BO).
instance_id Instance ID.
init_value Initial Present Value.
name Object Name string.

Returns:

SYN_OK on success, SYN_ERROR if database full.

function syn_bacnet_crc16¶

Calculate BACnet MS/TP Data CRC-16.

uint16_t syn_bacnet_crc16 (
    const uint8_t * data,
    size_t len
)

Parameters:

data Data buffer.
len Byte count.

Returns:

CRC-16 checksum value.

function syn_bacnet_crc8¶

Calculate BACnet MS/TP Header CRC-8.

uint8_t syn_bacnet_crc8 (
    const uint8_t * data,
    size_t len
)

Parameters:

data Data buffer.
len Byte count.

Returns:

CRC-8 checksum value.

function syn_bacnet_mstp_decode_frame¶

Decode a raw byte buffer into a BACnet MS/TP Frame structure.

bool syn_bacnet_mstp_decode_frame (
    const uint8_t * buf,
    size_t len,
    SYN_BACnet_MSTP_Frame * frame
)

Parameters:

buf Input raw frame byte array.
len Input byte count.
frame [out] Decoded MS/TP Frame structure.

Returns:

true if valid MS/TP frame header and CRC-8/CRC-16 match.

function syn_bacnet_mstp_encode_frame¶

Encode a complete BACnet MS/TP Frame.

size_t syn_bacnet_mstp_encode_frame (
    uint8_t frame_type,
    uint8_t dest_mac,
    uint8_t src_mac,
    const uint8_t * payload,
    uint16_t payload_len,
    uint8_t * out_buf
)

Parameters:

frame_type Frame Type enum.
dest_mac Destination MAC address.
src_mac Source MAC address.
payload Payload buffer (can be NULL if payload_len == 0).
payload_len Payload byte count.
out_buf Destination output buffer (must be >= payload_len + 10 bytes).

Returns:

Total encoded frame byte count.

function syn_bacnet_node_init¶

Initialize a BACnet MS/TP Node context.

SYN_Status syn_bacnet_node_init (
    SYN_BACnet_Node * node,
    uint8_t mac_address,
    uint32_t device_id
)

Parameters:

node Node handle.
mac_address Local MAC address (0..127).
device_id BACnet Device Instance ID (0..4194302).

Returns:

SYN_OK on success.

function syn_bacnet_node_process¶

Process an incoming BACnet MS/TP frame and generate a response if required.

SYN_Status syn_bacnet_node_process (
    SYN_BACnet_Node * node,
    const SYN_BACnet_MSTP_Frame * rx_frame,
    SYN_BACnet_MSTP_Frame * tx_frame,
    bool * has_tx
)

Parameters:

node Node context.
rx_frame Incoming received frame.
tx_frame [out] Outgoing response frame structure.
has_tx [out] Set to true if a response frame must be transmitted.

Returns:

SYN_OK on success.

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