C2MS12 — Inconsistent Fields MVAL Response and AMVAL Response

The AMVAL Response and AMVAL Data messages mostly line up with MVAL Response and MVAL Data messages, but not quite. The AMVAL Response, for example, contains no samples, which are present for all of MVAL Response, MVAL Data and AMVAL Data. Also, AMVAL Response, contains a Product Subtype Category not found in any of the others. This needs analysis and convergence to align these messages better.

Probably just need to do some analysis regarding comparative usages and fields to determine if it is correct as-is and if not, make them more consistent.

One item of note is that there will only ever be one MVAL Data Response Message, but may be multiple AMVAL Data Response Messages. This difference could at least be highlighted a little better. OK in 1.2 because of C2MS12-119, but really it needs to be analyzed for how to bring these in greater conformance. The reason for this particular difference seems to be that the AMVAL REQ/RESP has a finite end (see descr of STOP-TIME in AMVAL REQ: "Requested stop time of the mnemonic values to be retrieved from the telemetry archive. Defaults to the end of the telemetry archive") while MVAL can be no-end. This is also manifested in the concept of START and STOP request types in MVAL REQ, which don't exist in AMVAL REQ.

There is a related issue regarding required versus optional fields that is being resolved in C2MS12-42.