C2MS — Directive Request: strings, UNIQUE-ID and correlation IDs

• (Directive Request) Section 7.4.1

• Note that directive strings are highly vendor-specific
• There needs to be a unique ID that is set by the directive requester, not just the API. Otherwise, retrying is not deterministic. (Maybe the other side got the first directive. Maybe it didn’t. Sending the same request twice when the first was received might be dangerous.)
• Table 8-3: UNIQUE-ID is filled in by the transport/bus layer, not the user application, so this does not remove the need for correlation IDs

*Add field REQUEST-ID to all REQ, RESP, and applicable MSG messages *

Field is set by requestor and echo'd by responder in RESP and MSG messages. Same Request-ID will mean replacement, else, new request.

Added field REQUEST-ID to all REQ messages. Field is: Required, U16, "ID to identify the request message – if different request messages have the same value, the request is a replacement; else, it is a new request."

Added field REQUEST-ID to all RESP messages. Field is: Required, U16, "This field’s value is to be the same as the REQUEST-ID in the associated REQ message."

Added field REQUEST-ID to the MSG messages that have associated REQ and RESP messages. Field is: Required, U16, "This field’s value is to be the same as the REQUEST-ID in the associated REQ message."