How to get Enum value in OPC

[MatthewBoss96]

I am wondering how I can see the value of the enum in OPC UA.
Currently I have:
async def EnumTest(self, server, idx:int, name:str) -> Struct: await new_enum(server, idx, name, [ "UNDEFINED", "GOOD", "BAD", ])

self.EnumTest(self.server, self.idx, "EnumerateTest")

self.server.load_data_type_definitions()

await self.add_variable(self.Test, self.idx, "EnumTest", "Test for enumerate", ua.EnumerateTest.UNDEFINED)

When I view the EnumTest value in OPC UA I see:

How do I see the enum as well? So Value : 0 (UNDEFINED) instead of Value : 0?

[schroeder-]

You need to pass the nodeid of your enumtype to add_variable:

async def EnumTest(self, server, idx:int, name:str) -> Struct: 
     enum_node = await new_enum(server, idx, name, [ "UNDEFINED", "GOOD", "BAD", ]) 
     self.EnumTest(self.server, self.idx, "EnumerateTest")
     await self.server.load_data_type_definitions()  
     await self.add_variable(self.Test, self.idx, "EnumTest", "Test for enumerate", ua.EnumerateTest.UNDEFINED, enum_node)

[AndreasHeine]

enums in opcua are just int32! the string values are provided in the DataTypeDefinitions!

so you can basically scan them and construct your own Enum from that!

not sure if "load_data_type_definitions()" does that for you but i guess @schroeder- would not post it if not ;)

so basically you need to resolve the int value to the enum string value right!?

[schroeder-]

@MatthewBoss96 you are missing the await for load_data_type_definitions

async def EnumTest(self, server, idx:int, name:str) -> Struct: 
     enum_node = await new_enum(server, idx, name, [ "UNDEFINED", "GOOD", "BAD", ]) 
     self.EnumTest(self.server, self.idx, "EnumerateTest")
     await self.server.load_data_type_definitions()  
     await self.add_variable(self.Test, self.idx, "EnumTest", "Test for enumerate", ua.EnumerateTest.UNDEFINED, enum_node)

[MatthewBoss96]

@schroeder- I already added the await to the load_data_type_definitions(), but I will try the tips of @AndreasHeine. Thanks both for replying! I will let you know about the progress

[AndreasHeine]

@MatthewBoss96 usually you should already have the enum after loading via "load_data_type_definitions()"!

from asyncua import ua

'''
class NamingRuleType(IntEnum):
    """
    https://reference.opcfoundation.org/v104/Core/docs/Part3/8.29
    :ivar Mandatory:
    :vartype Mandatory: 1
    :ivar Optional:
    :vartype Optional: 2
    :ivar Constraint:
    :vartype Constraint: 3
    """
    Mandatory = 1
    Optional = 2
    Constraint = 3
'''

member = ua.NamingRuleType.Mandatory
print("Value:", member.value)
print("String:", member.name)


member = ua.NamingRuleType(1)
print("Value:", member.value)
print("String:", member.name)

Value: 1
String: Mandatory
Value: 1
String: Mandatory

[MatthewBoss96]

Goodmorning @schroeder- @AndreasHeine , I just discovered the problem. I was using a custom made function of add_variable instead of the in-built add_variable of asyncua. The solution was to use the inbuilt version:

enum_node = await new_enum(self.server, self.idx, "EnumerateTest", [ "UNDEFINED", "GOOD", "BAD", ]) 
await self.server.load_data_type_definitions() 
self.enumTest = await self.Test.add_variable(self.idx, "my_enum", ua.EnumerateTest.UNDEFINED, datatype=enum_node.nodeid)

Thanks for replying so quickly and being so involved in the community. Keep up the good work!