S2f33

S2F33/S2F34 is the SECS-II message pair the host uses to define a report — naming a Report ID (RPTID) and specifying exactly which Status Variables or Data Variables that report should contain — which is the first of three setup steps GEM-compliant event reporting requires before any data actually starts flowing to the host automatically. Defining a report on its own does nothing yet; S2F33 (Define Report) just tells the equipment "when I later ask for report RPTID_5, it should contain these specific SVIDs/DVIDs in this order," and S2F34 (Define Report Acknowledge) confirms the equipment accepted that definition — the report still has to be linked to a triggering event and then enabled before it ever actually gets sent.

The three-step separation (define, link, enable) rather than a single combined setup message exists because each step changes independently in practice — a host might redefine a report's variable list without changing which collection event triggers it, or might temporarily disable reporting for a report/event link it wants to keep configured for later, and collapsing all three into one message would force the host to resend the entire configuration every time only one part of it actually needs to change. This is exactly the same economy-of-change principle that shows up throughout SECS/GEM's design: the protocol separates concerns that change independently so that modifying one doesn't require retransmitting everything else.

S2F33/S2F34 only makes sense in the context of the full three-step setup — S2F35/S2F36 (Link Event Reports) ties the defined report to a specific Collection Event ID, and S2F37/S2F38 (Enable/Disable Event Reporting) turns that linked report on or off, with the actual data arriving afterward through S6F11/S6F12 (Collection Event Reporting) once every step has been completed.