class OPCHandler:
def __init__(self,
endpoint,
user,
password,
security=None,
cert_path=None,
private_key=None):
self._endpoint = endpoint
self.client = Client(endpoint)
self.client.set_user(user)
self.client.set_password(password)
'''
1. OPC UA Server "Zertifikate autom. akzeptieren" muss aktiv sein sonst Exception "BadSecurityChecksFailed"
2. Wenn Security != None
security übersetzen in entsprechenden Aufruf aus asyncua.crypto.security_policies
cert_path + key als raw string
z.B.:
cert = f"certificates/peer-certificate-example.der"
private_key = f"certificates/peer-private-key-example.pem"
'''
if security is not None:
self.client.set_security(security, cert_path, private_key)
logging.debug("Init successfully for endpoint: %r", endpoint)
return
async def __aenter__(self):
logging.debug("Trying to connect to endpoint: %r", self._endpoint)
await self.client.connect()
return self.client
async def __aexit__(self, exc_type, exc_val, exc_tb):
await self.client.disconnect()
async def task(loop):
url = "opc.tcp://192.168.2.64:4840"
# url = "opc.tcp://localhost:4840/freeopcua/server/"
try:
client = Client(url=url)
client.set_user('test')
client.set_password('test')
# client.set_security_string()
await client.connect()
# Client has a few methods to get proxy to UA nodes that should always be in address space such as Root or Objects
root = client.get_root_node()
_logger.info("Objects node is: %r", root)
# Node objects have methods to read and write node attributes as well as browse or populate address space
_logger.info("Children of root are: %r", await root.get_children())
tree = await browse_nodes(client.get_objects_node())
_logger.info('Node tree: %r', tree)
except Exception:
_logger.exception('error')
finally:
await client.disconnect()
async def _serial_poller_async(tpp):
"""Poll OPCUA agent data.
Args:
tpp: TargetDataPoints object
Returns:
target_datapoints: TargetDataPoints object
"""
# Initialize key variables
connected = False
# Test for validity
if isinstance(tpp, TargetPollingPoints) is False:
return None
if isinstance(tpp.target, OPCUAauth) is False:
return None
if tpp.valid is False:
return None
# Create URL for polling
ip_target = tpp.target.ip_target
ip_port = tpp.target.ip_port
username = tpp.target.username
password = tpp.target.password
url = 'opc.tcp://{}:{}'.format(ip_target, ip_port)
# Intialize data gathering
target_datapoints = TargetDataPoints(ip_target)
# Create a client object to connect to OPCUA server
client = Client(url=url)
client.set_user(username)
client.set_password(password)
# Connect
try:
await client.connect()
connected = True
except:
log_message = (
'Authentication for polling target {} is incorrect'.format(url))
log.log2warning(51011, log_message)
pass
if connected is True:
for point in tpp.data:
# Make sure we have the right data type
if isinstance(point, PollingPoint) is False:
log_message = ('''\
Invalid polling point {} for OPC UA URL {}'''.format(point, url))
log.log2info(51012, log_message)
continue
# Get data
address = point.address
try:
node = client.get_node(address)
value = await node.read_value()
except BadNodeIdUnknown:
log_message = ('''\
OPC UA node {} not found on server {}'''.format(address, url))
log.log2warning(51015, log_message)
continue
except:
_exception = sys.exc_info()
log_message = ('OPC UA server communication error')
log.log2exception(51014, _exception, message=log_message)
log_message = ('''\
Cannot get value from polling point {} for OPC UA URL {}\
'''.format(address, url))
log.log2info(51013, log_message)
continue
# Create datapoint
if bool(point.multiplier) is True:
if is_numeric(value) is True and (is_numeric(point.multiplier)
is True):
value = value * point.multiplier
else:
value = 0
datapoint = DataPoint(address, value)
datapoint.add(DataPointMetadata('OPCUA Server', ip_target))
target_datapoints.add(datapoint)
# Disconnect client
await client.disconnect()
return target_datapoints
