async def read_node_attribute(self, nodeId, attribute):
"""
Read node attribute based on given arguments.
Giving correct dataType for value and node speeds
up the write operation.
Arguments Example
nodeId: Target nodeId "ns=2;i=2"
attribute: Target attribute of node "Value"
Results
OPCUAVar: OPC UA variable object <object>
readTime: Time taken for read (ns) 12345678
"""
rv = ua.ReadValueId()
if nodeId == "":
rv.NodeId = ua.NodeId.from_string(server.rootNodeId)
else:
rv.NodeId = ua.NodeId.from_string(nodeId)
rv.AttributeId = ua.AttributeIds[attribute]
params = ua.ReadParameters()
params.NodesToRead.append(rv)
result, readTime = await self.read(params)
if attribute == "Value":
return result[0], readTime
else:
return result[0]
def get_attributes(self, nodes, attr):
self.logger.info("get_attribute")
request = ua.ReadRequest()
for node in nodes:
rv = ua.ReadValueId()
rv.NodeId = node
rv.AttributeId = attr
request.Parameters.NodesToRead.append(rv)
data = self._uasocket.send_request(request)
response = struct_from_binary(ua.ReadResponse, data)
response.ResponseHeader.ServiceResult.check()
return response.Results
def create_monitored_items(sub, dirty_nodes, attr):
mirs = []
for dirty_node in dirty_nodes:
try:
node_var = Node(sub.server, NodeId().from_string(dirty_node["node"]))
rv = ua.ReadValueId()
rv.NodeId = node_var.nodeid
rv.AttributeId = attr
# rv.IndexRange //We leave it null, then the entire array is returned
mparams = ua.MonitoringParameters()
with sub._lock:
sub._client_handle += 1
mparams.ClientHandle = sub._client_handle
mparams.SamplingInterval = dirty_node["samplingInterval"]
mparams.QueueSize = dirty_node["queueSize"]
mparams.DiscardOldest = dirty_node["queueDiscardOldest"] == "True"
if dirty_node["filter"] != "None":
try:
mfilter = DataChangeFilter()
#DataChangeTrigger(0) = Status, DataChangeTrigger(1) = StatusValue, DataChangeTrigger(2) = StatusValueTimestamp
mfilter.Trigger = DataChangeTrigger[dirty_node["filter"]["Trigger"]]
# DeadbandType(0) = None, DeadbandType(1) = Absolute, DeadbandType(2) = Percent
mfilter.DeadbandType = DeadbandType[dirty_node["filter"]["DeadbandType"]]
mfilter.DeadbandValue = dirty_node["filter"]["DeadbandValue"]
except:
mfilter = None
print(f"\n\nWARNING: Can't apply filter on node {dirty_node['node']}")
else:
mfilter = None
if mfilter:
mparams.Filter = mfilter
mir = ua.MonitoredItemCreateRequest()
mir.ItemToMonitor = rv
mir.MonitoringMode = ua.MonitoringMode.Disabled if dirty_node["monitoringMode"] == "Disabled" else ua.MonitoringMode.Sampling if dirty_node["monitoringMode"] == "Sampling" else ua.MonitoringMode.Reporting
mir.RequestedParameters = mparams
mirs.append(mir)
except:
print("\nUnable to create monitored item for node {dirty_node['node']}")
mids, results = sub_monitored_items_creation(sub, mirs)
for i, r in enumerate(results):
if dirty_node["samplingInterval"] != r.RevisedSamplingInterval or dirty_node["queueSize"] != r.RevisedQueueSize:
print(f"\nServer has changed monitored item properties for node {dirty_node['node']}")
print(f"Monitored item id: {r.MonitoredItemId}")
print(f"Revised SamplingInterval: {r.RevisedSamplingInterval}")
print(f"Revised QueueSize: {r.RevisedQueueSize}")
print(f"Filter Result: {r.FilterResult}\n")
return mids
def get_attribute(self, attr):
"""
Read one attribute of a node
result code from server is checked and an exception is raised in case of error
"""
rv = ua.ReadValueId()
rv.NodeId = self.nodeid
rv.AttributeId = attr
params = ua.ReadParameters()
params.NodesToRead.append(rv)
result = self.server.read(params)
result[0].StatusCode.check()
return result[0]
def get_attributes(self, attrs):
"""
Read several attributes of a node
list of DataValue is returned
"""
params = ua.ReadParameters()
for attr in attrs:
rv = ua.ReadValueId()
rv.NodeId = self.nodeid
rv.AttributeId = attr
params.NodesToRead.append(rv)
results = self.server.read(params)
return results
async def batch_load_fn(self, attributeKeys):
"""
Iterates through the attributeKeys and retrieves data
from OPC UA servers based on the attributeKey values.
Arguments
attributeKeys: List of strings with required infromation
to retrieve the attributes from OPC UA servers.
Template: "Server/NodeId/Attribute"
Example: "TestServer/ns=2;i=2/Value"
Results
sortedResults: List of values returned by the OPC UA server
for each attribute. Also includes OPC UA read
time with each attribute.
In same order as attributeKeys.
Example: [<opcua_object>, readTime]
"""
servers = defaultdict(list)
i = 0
for attribute in attributeKeys:
info = attribute.split("/")
servers[info[0]].append([i, info[1], info[2]])
i += 1
sortedResults = [None] * len(attributeKeys)
for serverName, attributes in servers.items():
params = ua.ReadParameters()
server = getServer(serverName)
for info in attributes:
rv = ua.ReadValueId()
if info[1] == "":
rv.NodeId = ua.NodeId.from_string(server.rootNodeId)
else:
rv.NodeId = ua.NodeId.from_string(info[1])
rv.AttributeId = ua.AttributeIds[info[2]]
params.NodesToRead.append(rv)
results, readTime = await server.read(params)
i = 0
for info in attributes:
sortedResults[info[0]] = [results[i], readTime]
i += 1
return sortedResults
def make_monitored_item_request(self, subscription, node, attr, sampling_interval, client_handle, filter, queuesize, discard_oldest):
rv = ua.ReadValueId()
rv.NodeId = node.nodeid
rv.AttributeId = attr
mparams = ua.MonitoringParameters()
with subscription._lock:
subscription._client_handle = client_handle
mparams.ClientHandle = subscription._client_handle
mparams.SamplingInterval = sampling_interval
mparams.QueueSize = queuesize
mparams.DiscardOldest = discard_oldest
if filter:
mparams.Filter = filter
mir = ua.MonitoredItemCreateRequest() #stack request
mir.ItemToMonitor = rv
mir.MonitoringMode = ua.MonitoringMode.Reporting
mir.RequestedParameters = mparams
return mir
def _make_monitored_item_request(self, node, attr, mfilter, queuesize):
rv = ua.ReadValueId()
rv.NodeId = node.nodeid
rv.AttributeId = attr
# rv.IndexRange //We leave it null, then the entire array is returned
mparams = ua.MonitoringParameters()
with self._lock:
self._client_handle += 1
mparams.ClientHandle = self._client_handle
mparams.SamplingInterval = self.parameters.RequestedPublishingInterval
mparams.QueueSize = queuesize
mparams.DiscardOldest = True
if mfilter:
mparams.Filter = mfilter
mir = ua.MonitoredItemCreateRequest()
mir.ItemToMonitor = rv
mir.MonitoringMode = ua.MonitoringMode.Reporting
mir.RequestedParameters = mparams
return mir
async def get_variable_nodes(self,
node,
nodeClass=2,
variableList=None,
depth=0,
maxDepth=10):
"""
Eats a list of node object(s).
Recursively finds nodes under given nodes that have given nodeClass.
Returns node objects in a list.
"""
if variableList is None:
variableList = []
depth += 1
if depth >= maxDepth:
return variableList
nodes = node.get_children()
params = ua.ReadParameters()
for node in nodes:
rv = ua.ReadValueId()
rv.NodeId = node.nodeid
rv.AttributeId = ua.AttributeIds.NodeClass
params.NodesToRead.append(rv)
results = []
if len(params.NodesToRead) > 0:
results, readTime = await self.read(params)
for i in range(len(results)):
if nodeClass == results[i].Value.Value:
variableList.append(nodes[i])
await self.get_variable_nodes(node=nodes[i],
nodeClass=nodeClass,
variableList=variableList,
depth=depth)
return variableList
def _subscribe(self, node, attr, mfilter=None, queuesize=0):
rv = ua.ReadValueId()
rv.NodeId = node.nodeid
rv.AttributeId = attr
# rv.IndexRange //We leave it null, then the entire array is returned
mparams = ua.MonitoringParameters()
self._client_handle += 1
mparams.ClientHandle = self._client_handle
mparams.SamplingInterval = self.parameters.RequestedPublishingInterval
mparams.QueueSize = queuesize
mparams.DiscardOldest = True
if mfilter:
mparams.Filter = mfilter
mir = ua.MonitoredItemCreateRequest()
mir.ItemToMonitor = rv
mir.MonitoringMode = ua.MonitoringMode.Reporting
mir.RequestedParameters = mparams
params = ua.CreateMonitoredItemsParameters()
params.SubscriptionId = self.subscription_id
params.ItemsToCreate.append(mir)
params.TimestampsToReturn = ua.TimestampsToReturn.Neither
with self._lock:
results = self.server.create_monitored_items(params)
result = results[0]
result.StatusCode.check()
data = SubscriptionItemData()
data.client_handle = mparams.ClientHandle
data.node = node
data.attribute = attr
data.server_handle = result.MonitoredItemId
data.mfilter = ua.downcast_extobject(result.FilterResult)
self._monitoreditems_map[mparams.ClientHandle] = data
return result.MonitoredItemId
def add(self, attr):
rv = ua.ReadValueId()
rv.NodeId = self.nodeid
rv.AttributeId = attr
self.params.NodesToRead.append(rv)
self._debug_attr.append(attr)
def create_monitored_items(self, nodes, index):
monitored_items = []
if not isinstance(nodes, list):
nodes = [nodes]
for node in nodes:
# Set item to monitor
rv = ua.ReadValueId()
rv.NodeId = node.nodeid
rv.AttributeId = ua.AttributeIds.Value
# Set monitoring parameters
mparams = ua.MonitoringParameters()
self._client_handle += 1
mparams.ClientHandle = self._client_handle
mparams.SamplingInterval = self.samplingInterval
mparams.QueueSize = self.queueSize
mparams.DiscardOldest = self.discardOldest
# Create monitored item filter
if self.dataChangeFilter:
mfilter = ua.DataChangeFilter()
mfilter.Trigger = ua.DataChangeTrigger(self.dataChangeTrigger)
if self.deadbandType == ua.DeadbandType.Absolute:
if node.get_data_value(
).Value.VariantType in self.numericTypes:
mfilter.DeadbandType = self.deadbandType
mfilter.DeadbandValue = self.deadbandValue # absolute float value or from 0 to 100 for percentage deadband
else:
self.deadbandType = ua.DeadbandType.None_
mfilter.DeadbandType = self.deadbandType
elif self.deadbandType == ua.DeadbandType.Percent:
has_EURange = False
if node.get_type_definition(
).Identifier == ua.object_ids.ObjectIds.AnalogItemType:
# Get node properties
descriptions = node.get_references(
ua.ObjectIds.HasProperty,
ua.BrowseDirection.Forward, ua.NodeClass.Variable,
False)
for desc in descriptions:
if desc.BrowseName.Name == "EURange" and self.get_node(
desc.NodeId).get_value() is not None:
has_EURange = True
if has_EURange:
mfilter.DeadbandType = self.deadbandType
mfilter.DeadbandValue = self.deadbandValue # absolute float value or from 0 to 100 for percentage deadband
else:
self.deadbandType = ua.DeadbandType.None_
mfilter.DeadbandType = self.deadbandType
else:
mfilter = None
mparams.Filter = mfilter
# Create monitored item request
mir = ua.MonitoredItemCreateRequest()
mir.ItemToMonitor = rv
mir.MonitoringMode = ua.MonitoringMode.Reporting
mir.RequestedParameters = mparams
# Append to list
monitored_items.append(mir)
sub, monitored_items_handles = self._datachange_subs[index]
handles = sub.create_monitored_items(monitored_items)
for i in range(len(handles)):
handle = handles[i]
if type(handle) == ua.StatusCode:
handle.check()
monitored_items_handles[nodes[i].nodeid] = handle
