This needs to be clarified for all methods (not specifically for Part 18) Moving to Part 4.

Need a discussion in F2F

I saw at the IOP that all server that load NS0 from Nodeset have the same problem. They expose many Methods that return errors like BadNotImplemented and have Variables with Value NULL / Good Status

In Part 6 we added the following statement in nodeset XML schema (F.8 UAVariable):
If a Value is not provided and a UANodeSet is used to initialize a Server AddressSpace then the Server shall report a StatusCode of Bad_WaitingForInitialData or choose a default Value consistent with the DataType and ValueRank.

In Part 4, we have the following statement in 7.11.5 StatusCode assigned to a value:
If the Server has no known value - in particular when Severity is BAD, it shall return a NULL value.

This does not say explicit that NULL value and Good Status is not allowed.
It would be good if we would clarify this consistent in the same release.

Discussion in WG meeting:
Define a new deticated status code in Part 4
Update description in 7.11.5 to state that either a default value is provided or NULL with the new status code.

Added status code
Bad_NoInitialData
There is no initial data available.
The status is used if a Variable is created and no default value or no initial value is available.

Added clarification to description in 7.11.5:
If the related DataType is not BaseDataType, the Severity shall be BAD if the value is NULL. If a Variable is created and no default value or initial value is available, the StatusCode shall be Bad_NoInitialData.

Agreed to changes edited in web meeting.

This issue was resolved for Variables but not for Methods.

What should be the Method result code if a mandatory Method is not supported for the instance. E.g. Enable/Disable of Conditions if the underlying alarm system does not support enable/disable.

Is Bad_NotSupported a good option?
We have also Bad_NotImplemented but I see this more like a default value that would be returned if there is no defined handling at all (or default return generated by a code generator for a empty Method implementation prototype code).

Table 67 – Call Operation Level Result Codes
Added Bad_NotSupported
See Table 183 for the description of this result code.
The Method is not supported for the Object instance.

Agreed to changes in Virtual F2F.