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IDProjectCategoryView StatusLast Update
000353510000-003: Address SpaceSpecpublic2017-01-10 16:26
ReporterKarl Deiretsbacher Assigned Tojeffhardingabb  
PrioritynormalSeverityminorReproducibilityhave not tried
Status closedResolutionfixed 
Product Version1.03 
Summary0003535: Need attribute to indicate atomicity
Description

Some systems - in particular in hard realtime control - do not allow inhibiting interrupts and therefore cannot guarantee atomic access in all cases, in particular for variables that are structures or arrays.
Most of these systems will allow enforcing atomicity for a limited number of values. It is therefore considered necessary to discover this characteristic so that reliable behavior can be assured in a plant (e.g. for M2M).

Proposal: Add an optional attribute ("atomicity") per Variable.

TagsNo tags attached.
Commit Version
Fix Due Date

Relationships

related to 0003536 closedjeffhardingabb 10000-003: Address Space No access level flag for optional IndexRange write 
related to 0003311 closedrandyarmstrong 10000-006: Mappings New DataTypeDefinition Attribute 

Activities

Matthias Damm

2016-10-06 10:53

developer   ~0007191

My recommendation is to add a new bit mask attribute instead of a Boolean attribute just for atomicity.

We extended the AccessLevel in the past with additional related information. But the AccessLevel mask is full.

It is already foreseeable that we need additional flags e.g. an indication that a variable cannot be used for real-time communication. CANopen has such flags in addition to simple read/write (read/write flags + cyclic/real-time access flags + safety flags).

My proposal would be to introduce an AccessRestrictions or AccessLimitations Attribute that is a bit mask.

If a flag is set in this mask, it indicates a restriction e.g. no atomicity or no real-time access. The default would be false.

jeffhardingabb

2016-12-09 12:08

developer   ~0007473

Added attribute Atomicity in Part 3 section 5.6.2

Matthias Damm

2016-12-10 13:01

developer   ~0007503

There are more requirements we need to cover with the new attribute and therefore we should use a more generic name and add other features (see 0003536) and ma concrete proposal in 'OPC UA Part 3 - Address Space Model 1.04.05 Draft Specification Jim Luth Comments_MD.docx'

Karl Deiretsbacher

2016-12-13 20:06

developer   ~0007518

The attribute is now called AccessLevelEx and new Bits are already included.

Jim Luth

2017-01-10 16:26

administrator   ~0007706

Agreed to changes edited in telecon.

Issue History

Date Modified Username Field Change
2016-09-17 07:03 Karl Deiretsbacher New Issue
2016-09-20 16:04 Jim Luth Assigned To => Wolfgang Mahnke
2016-09-20 16:04 Jim Luth Status new => assigned
2016-10-06 10:53 Matthias Damm Note Added: 0007191
2016-11-29 14:10 Jim Luth Assigned To Wolfgang Mahnke => jeffhardingabb
2016-12-09 12:08 jeffhardingabb Note Added: 0007473
2016-12-09 12:08 jeffhardingabb Status assigned => resolved
2016-12-09 12:08 jeffhardingabb Fixed in Version => 1.04
2016-12-09 12:08 jeffhardingabb Resolution open => fixed
2016-12-10 12:59 Matthias Damm Relationship added related to 0003536
2016-12-10 13:01 Matthias Damm Note Added: 0007503
2016-12-10 13:01 Matthias Damm Status resolved => feedback
2016-12-10 13:01 Matthias Damm Resolution fixed => reopened
2016-12-10 22:00 Matthias Damm Relationship added related to 0003311
2016-12-13 20:06 Karl Deiretsbacher Note Added: 0007518
2016-12-13 20:06 Karl Deiretsbacher Status feedback => assigned
2016-12-13 20:06 Karl Deiretsbacher Status assigned => resolved
2016-12-13 20:06 Karl Deiretsbacher Resolution reopened => fixed
2017-01-10 16:26 Jim Luth Note Added: 0007706
2017-01-10 16:26 Jim Luth Status resolved => closed