Objectif :
Send and receive data with a VN1630A Vector device from python script.
Tools used
- python-can
- cantools
Details
I am currently trying to send and receive data from a python script on a CAN communication using a VN1630A device. I can see my device on Vector Hardware manager. No other applications are running when I trz except VScode and Vector HardWare Manager. I have configured 2 channel on the software to a specific "python-can" application.
I am using the specific Vector interface of cantools to connect.
I made a dbc Can file with specific messages.
my python script
from typing import Optional
import can
import cantools
from can.interfaces import vector
from can import typechecking
MASTER_TO_SLAVE_MSG = "Master_to_slave_standard_msg"
class MasterVectorCAN():
def __init__(self, channel, dbc_file_path):
self.channel = channel
self.dbc_file_path = dbc_file_path
self.bus = None
self.db = None
def open(self):
"""
Ouvre le bus de communication.
"""
try:
self.bus = vector.VectorBus(bitrate=500000, channel=self.channel,app_name="python-can")
return True
except Exception as e:
print(f"Erreur lors de l'ouverture du bus : {e}")
return False
def send(self, counter, Command_sg,Num_selector,Table_Selector, extended_id=False):
"""
Envoie un message sur le bus de communication.
Args:
message_id (int): L'identifiant du message CAN.
data (bytes): Les données à envoyer.
extended_id (bool, optional): Si True, utilise un identifiant étendu (29 bits). Sinon, utilise un identifiant standard (11 bits). Par défaut, False.
Returns:
bool: True si l'envoi a réussi, False sinon.
"""
try:
data = {"Counter":counter,"Command_sg":Command_sg,"Num_selector":Num_selector,"Table_Selector":Table_Selector}
can_msg = self.encode_message(MASTER_TO_SLAVE_MSG,data=data)
self.bus.send(can_msg)
return True
except Exception as e:
print(f"Erreur lors de l'envoi du message : {e}")
return False
def receive(self, timeout=None):
"""
Reçoit un message depuis le bus de communication.
Args:
timeout (float, optional): Temps d'attente maximal en secondes. Si None, la fonction bloque jusqu'à ce qu'un message soit reçu. Par défaut, None.
Returns:
can.Message: Le message reçu, ou None en cas d'expiration du timeout.
"""
try:
return self.bus.recv(timeout=timeout)
except Exception as e:
print(f"Erreur lors de la réception du message : {e}")
return None
def load_dbc_file(self):
"""
Charge la configuration depuis un fichier DBC.
Returns:
bool: True si le chargement a réussi, False sinon.
"""
try:
self.bus.set_filters([{"dbc": self.dbc_file_path}])
self.db = cantools.database.load_file(self.dbc_file_path)
self.master_msg = self.db.get_message_by_name(MASTER_TO_SLAVE_MSG)
return True
except Exception as e:
print(f"Erreur lors du chargement du fichier DBC : {e}")
return False
def close(self):
"""
Ferme le bus de communication.
"""
if self.bus is not None:
self.bus.shutdown()
self.bus = None
if __name__ == "__main__":
channel = 0 # Channel du bus CAN Vector (peut varier selon la configuration matérielle)
dbc_file_path = "C:\\Users\\MPI4ABT\\Documents\\MATLAB\\Can_db.dbc"
interface = "vector"
vector_can = MasterVectorCAN(channel, dbc_file_path)
print("Instantiated")
if vector_can.open():
print("Opened")
vector_can.load_dbc_file()
# Exemple d'envoi de données
message_id = 0x123
data = b'\x01\x02\x03\x04\x05\x06\x07\x08'
vector_can.send(counter=b'x01',Command_sg=b'x01',Num_selector=b'0011',Table_Selector=b'x01',extended_id=False)
# Exemple de réception de données avec un timeout de 1 seconde
received_message = vector_can.receive(timeout=1)
if received_message:
print(f"Message reçu : {received_message}")
vector_can.close()
I am currently sending a random message and receiving whatever. However, When I run my script, the debugger blocks on self.bus = vector.VectorBus(bitrate=500000, channel=self.channel,app_name="python-can")without any error, it just blocks. There is no similar issues on the python-can documentation (Using the version 4.2.2). So it blocks on it and do not go further.
No way found to solve this issue except diving into the vector specific API which could take me a year to resolve this issue.
