View Issue Details
ID | Project | Category | View Status | Date Submitted | Last Update |
---|---|---|---|---|---|
0004779 | 10000-003: Address Space | Api Change | public | 2019-06-07 13:34 | 2022-07-19 16:32 |
Reporter | David Levine | Assigned To | Jeff Harding | ||
Priority | normal | Severity | major | Reproducibility | always |
Status | assigned | Resolution | open | ||
Summary | 0004779: Define constraints on Variables with ValueRank of 0, -2 and -3, and on data type | ||||
Description | Some devices and networks need to know at configuration time what the data payloads will be. e.g. TSN cannot be scheduled without knowing max payload size, PLCs need to know max processing time to copy data around, etc. The current spec allows servers to defer defining array sizes until runtime, and in some cases the client will not know what it is getting until it receives the data. For example, currently if a Variable has ValueRank = -2 the only reliable way to determine if it is an array or a scalar is to read the entire value and see how big it is. There is no guarantee that it wont change during the session or at the start of a new session. A similar problem would exist with arrays of variants, where each element is a different data type and size. This could be handled as a new profile/conformance unit, or to create subtypes with the additional behaviors specified. | ||||
Steps To Reproduce | Both the Softing demo server and the UnifiedAutomation demo server provide some examples of the problem. They do not have Variable nodes with ValueRank = -2 or -3, but they demonstrate different aspects of the issue. UAExpert provides a simple means of changing the array or matrix. The UA demo server allows the user to manually change the size and dimension of an array. When the client writes an array it does not use an IndexRange. When the server receives the array and it is a different size it replaces the current array with the new one - the ArrayDimensions value remains unchanged. You can also change the number and size of a multi-dimension array. The Softing demo server's dynamic arrays are constantly changing size - each time the Variable is read it returns a different length array. The ArrayDimensions is not updated. | ||||
Tags | No tags attached. | ||||
Commit Version | |||||
Fix Due Date | |||||
Date Modified | Username | Field | Change |
---|---|---|---|
2019-06-07 13:34 | David Levine | New Issue | |
2021-04-14 17:29 | Jim Luth | Project | UA => Feature Requests |
2022-07-19 15:59 | Jim Luth | Project | Feature Requests => 10000-003: Address Space |
2022-07-19 15:59 | Jim Luth | Category | Feature Request => Api Change |
2022-07-19 15:59 | Jim Luth | Assigned To | => Jeff Harding |
2022-07-19 15:59 | Jim Luth | Status | new => assigned |
2022-07-19 16:01 | Jim Luth | Note Added: 0017153 |