async def setup_nodes(self):
"""
Set up some nodes as defined by spec
"""
uries = ['http://opcfoundation.org/UA/']
ns_node = Node(self.isession, ua.NodeId(ua.ObjectIds.Server_NamespaceArray))
await ns_node.set_value(uries)
params = ua.WriteParameters()
for nodeid in (ua.ObjectIds.Server_ServerCapabilities_OperationLimits_MaxNodesPerRead,
ua.ObjectIds.Server_ServerCapabilities_OperationLimits_MaxNodesPerHistoryReadData,
ua.ObjectIds.Server_ServerCapabilities_OperationLimits_MaxNodesPerHistoryReadEvents,
ua.ObjectIds.Server_ServerCapabilities_OperationLimits_MaxNodesPerWrite,
ua.ObjectIds.Server_ServerCapabilities_OperationLimits_MaxNodesPerHistoryUpdateData,
ua.ObjectIds.Server_ServerCapabilities_OperationLimits_MaxNodesPerHistoryUpdateEvents,
ua.ObjectIds.Server_ServerCapabilities_OperationLimits_MaxNodesPerMethodCall,
ua.ObjectIds.Server_ServerCapabilities_OperationLimits_MaxNodesPerBrowse,
ua.ObjectIds.Server_ServerCapabilities_OperationLimits_MaxNodesPerRegisterNodes,
ua.ObjectIds.Server_ServerCapabilities_OperationLimits_MaxNodesPerTranslateBrowsePathsToNodeIds,
ua.ObjectIds.Server_ServerCapabilities_OperationLimits_MaxNodesPerNodeManagement,
ua.ObjectIds.Server_ServerCapabilities_OperationLimits_MaxMonitoredItemsPerCall):
attr = ua.WriteValue()
attr.NodeId = ua.NodeId(nodeid)
attr.AttributeId = ua.AttributeIds.Value
attr.Value = ua.DataValue(ua.Variant(10000), ua.StatusCode(ua.StatusCodes.Good))
attr.Value.ServerTimestamp = datetime.utcnow()
params.NodesToWrite.append(attr)
result = await self.isession.write(params)
result[0].check()
async def write_attribute(self, attributeid, datavalue):
"""
Set an attribute of a node
attributeid is a member of ua.AttributeIds
datavalue is a ua.DataValue object
"""
attr = ua.WriteValue()
attr.NodeId = self.nodeid
attr.AttributeId = attributeid
attr.Value = datavalue
params = ua.WriteParameters()
params.NodesToWrite = [attr]
result = await self.server.write(params)
result[0].check()
async def write_attribute(self, attributeid, datavalue, indexrange=None):
"""
Set an attribute of a node
attributeid is a member of ua.AttributeIds
datavalue is a ua.DataValue object
indexrange is a NumericRange (a string; e.g. "1" or "1:3".
See https://reference.opcfoundation.org/v104/Core/docs/Part4/7.22/)
"""
attr = ua.WriteValue()
attr.NodeId = self.nodeid
attr.AttributeId = attributeid
attr.Value = datavalue
attr.IndexRange = indexrange
params = ua.WriteParameters()
params.NodesToWrite = [attr]
result = await self.server.write(params)
result[0].check()
async def set_attributes(self, nodeids, datavalues, attributeid=ua.AttributeIds.Value):
"""
Set an attribute of multiple nodes
datavalue is a ua.DataValue object
"""
self.logger.info("set_attributes of several nodes")
request = ua.WriteRequest()
for idx, nodeid in enumerate(nodeids):
attr = ua.WriteValue()
attr.NodeId = nodeid
attr.AttributeId = attributeid
attr.Value = datavalues[idx]
request.Parameters.NodesToWrite.append(attr)
data = await self.protocol.send_request(request)
response = struct_from_binary(ua.WriteResponse, data)
response.ResponseHeader.ServiceResult.check()
return response.Results
async def main():
url = 'opc.tcp://localhost:4840/freeopcua/server/'
async with Client(url=url) as client:
uri = 'http://examples.freeopcua.github.io'
idx = await client.get_namespace_index(uri)
var = await client.nodes.root.get_child(
["0:Objects", f"{idx}:MyObject", f"{idx}:MyVariable"])
nb = 4000
start = time.time()
attr = ua.WriteValue()
attr.NodeId = var.nodeid
attr.AttributeId = ua.AttributeIds.Value
attr.Value = ua.DataValue(ua.Variant(1.0, ua.VariantType.Float))
params = ua.WriteParameters()
params.NodesToWrite = [attr]
for i in range(nb):
params.NodesToWrite[0].Value.Value.Value = i
result = await client.uaclient.write_value(params)
#result[0].check()
#await var.write_value(i)
print("\n Write frequency: \n", nb / (time.time() - start))
