View Issue Details
| ID | Project | Category | View Status | Date Submitted | Last Update |
|---|---|---|---|---|---|
| 0006829 | 10000-006: Mappings | Spec | public | 2021-04-21 09:49 | 2021-05-27 14:44 |
| Reporter | Mark Clemens | Assigned To | Randy Armstrong | ||
| Priority | normal | Severity | block | Reproducibility | always |
| Status | closed | Resolution | fixed | ||
| Summary | 0006829: 5.2.5 differentiates between a zero length array and a null array. A definition of what an "empty array" means is missing | ||||
| Description | In several places in the specification, the term "empty" is used in the context of arrays. E.g. In part 3 for the InputArguments and OutputArguments or part 9 for the ConditionId. empty can be a null array and empty can be an array with zero length For arrays there is no definition what it means for the mapping, when an array is empty. For other mappings, like for variants in 5.1.6 in part 6, it is clearly defined what "empty" means. | ||||
| Additional Information | Several server implementations exist, including the OPC Foundation Quickstart Alarms & Conditions Server, that accept both a null array and an array of zero length, in the select clause for the SimpleAttributeOperand for the ConditionId. At least one OPC UA server implementation is known that accepts only an array of zero length and causes interoperability issues with OPC UA clients that use a null array in the SimpleAttributeOperand for the ConditionId. | ||||
| Tags | No tags attached. | ||||
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| related to | 0006950 | closed | Matthias Damm | 10000-004: Services | 5.2.5 differentiates between a zero length array and a null array. A definition of what an "empty array" means is missing |
| related to | 0006965 | assigned | Alexander Allmendinger | Compliance Test Tool (CTT) Unified Architecture | 5.2.5 differentiates between a zero length array and a null array. A definition of what an "empty array" means is missing |
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Added text to 1.05 RC: 5.1.9 Null, Empty and Zero-Length Arrays The terms null, empty and zero-length are used to describe array values. A null array has no value. A zero-length or empty array is an array with 0 elements. Some DataEncodings will allow the distinction to be preserved on the wire, however, not all DevelopmentPlatforms will be able to preseve the distinction. For this reason, null, empty and zero length arrays are semantically the same for all DataEncodings. Decoders shall be able to handle all variations supported by the DataEncoding, however, decoders are not required to preserve the distinction. When testing for equality, applications shall treat null and empty arrays as equal. When a DevelopmentPlatform supports the distinction, writing and reading back an array value may result in null array becoming an empty array or vise versa. |
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Agreed to changes edited in telecon. Also agreed no Errata necessary. |
| Date Modified | Username | Field | Change |
|---|---|---|---|
| 2021-04-21 09:49 | Mark Clemens | New Issue | |
| 2021-05-13 05:45 | Randy Armstrong | Assigned To | => Randy Armstrong |
| 2021-05-13 05:45 | Randy Armstrong | Status | new => resolved |
| 2021-05-13 05:45 | Randy Armstrong | Resolution | open => fixed |
| 2021-05-13 05:45 | Randy Armstrong | Note Added: 0014359 | |
| 2021-05-18 15:20 | Jim Luth | Issue cloned: 0006950 | |
| 2021-05-18 15:20 | Jim Luth | Relationship added | related to 0006950 |
| 2021-05-18 15:31 | Jim Luth | Status | resolved => closed |
| 2021-05-18 15:31 | Jim Luth | Fixed in Version | => 1.05 |
| 2021-05-18 15:31 | Jim Luth | Note Added: 0014391 | |
| 2021-05-27 14:44 | Jim Luth | Issue cloned: 0006965 | |
| 2021-05-27 14:44 | Jim Luth | Relationship added | related to 0006965 |
