Pat Hascall has asked DM to look specifically at whether requirement CA-DM-CON-ICD-0004, "Camera Conditions Latency for All Data" can be relaxed or removed altogether. Note that this is a requirement of long standing, and that, although the latency value was stated as TBD, it was also stated to be consistent with the "cycle of delivery of raw data to the Archive Center", i.e., related to daytime operations as they were then conceived.
To summarize cartoons of our positions (Pat, correct me if I'm wrong):
Pat: The Camera already has a generic requirement flowed down from the OSS to publish telemetry. Adding this requirement just creates another very similar one to test, and does not really meaningfully additionally constrain the Camera, unless the latency is short (as in the present draft, 60 seconds), in which case there are worries about some types of infrequently-updated telemetry that simply cannot meet that requirement.
Gregory: The 60-second requirement was introduced in the expectation that it would be trivial to meet by just publishing all telemetry more or less as soon as it's available to publish. We understand the problem with infrequently-updated telemetry. It's difficult to craft a bulletproof text that accommodates that, and we are all under pressure not to write wishy-washy requirements. There is at present no baselined DM requirement for the 60-second requirement. By definition Data Release Production runs at much longer latencies, and the telemetry requirements of Calibration Products Production (which runs, among other times, in the afternoon to generate daily synthetic flats) are not yet baselined.
But I don't want to give up on a latency requirement altogether. DM does have a requirement to make Level 1 data products available within 24 hours, and those include the associated Observatory metadata - which includes Camera telemetry.
So I propose that we compromise on a 12-hour latency. I think that should handle all conceivable cases of low-frequency telemetry, and gives DM plenty of time to do any assimilation of metadata into the release of Level 1 data products.
I will edit this into the next draft.
Edits have been merged into LSE-69-20141004.docx, uploaded to Confluence.