780   What are 'unsupported trigger option at a control block?

Created: 04 Oct 2011

Status: In Force (green)

Part: Part 7-2 (2010; Edition 2)

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Clause: 14.2.2.11

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Category: Issue may impact interoperability of implementations of Edition 2

Issue

Part 7-2 states: If a BRCB does not support one or more of the trigger options, the attempt to set the TrgOp attribute to TRUE for one of these not supported values, shall cause a negative response of the SetReportControlValues service.
Unfortunately it is not clear what 'not supported' means:
a). the client tries to set trigger options unknown by the client (e.g. because they are defined by another edition of the standard). b). the trigger option does not apply to the implemented data model or the defined data set.
c). one of the server level trigger options (GI, Integrity period) is enabled.

Proposal

Clarify what 'Not supported' means. Suggested are the cases identified above, with following solution:
a). a negative ack is needed.
b). this case is irrelevant from the server / stack point of view, i.e. a positive ack is OK.
c). This MUST be supported by all servers, so again a negative ack is no choice....
Note that due to point a). above a client must be prepared to handle negative acks.