{"action":"created","issue":{"url":"https://api.github.com/repos/m-labs/artiq/issues/40","repository_url":"https://api.github.com/repos/m-labs/artiq","labels_url":"https://api.github.com/repos/m-labs/artiq/issues/40/labels{/name}","comments_url":"https://api.github.com/repos/m-labs/artiq/issues/40/comments","events_url":"https://api.github.com/repos/m-labs/artiq/issues/40/events","html_url":"https://github.com/m-labs/artiq/issues/40","id":89958619,"number":40,"title":"develop generic pattern to compensate for delays/latencies","user":{"login":"jordens","id":1338946,"avatar_url":"https://avatars2.githubusercontent.com/u/1338946?v=3","gravatar_id":"","url":"https://api.github.com/users/jordens","html_url":"https://github.com/jordens","followers_url":"https://api.github.com/users/jordens/followers","following_url":"https://api.github.com/users/jordens/following{/other_user}","gists_url":"https://api.github.com/users/jordens/gists{/gist_id}","starred_url":"https://api.github.com/users/jordens/starred{/owner}{/repo}","subscriptions_url":"https://api.github.com/users/jordens/subscriptions","organizations_url":"https://api.github.com/users/jordens/orgs","repos_url":"https://api.github.com/users/jordens/repos","events_url":"https://api.github.com/users/jordens/events{/privacy}","received_events_url":"https://api.github.com/users/jordens/received_events","type":"User","site_admin":false},"labels":[{"id":226994765,"url":"https://api.github.com/repos/m-labs/artiq/labels/area:documentation","name":"area:documentation","color":"fbca04","default":false}],"state":"open","locked":false,"assignee":null,"assignees":[],"milestone":null,"comments":4,"created_at":"2015-06-21T20:47:52Z","updated_at":"2017-06-09T09:25:16Z","closed_at":null,"body":"The reference plane for \"time\" is defined to be the rtio-clock side of the FIFOs, where the rtio counter lives. Latency compensation for delays happening from this plane to any other point in the downstream signal path (DDS DAC output, DDS amplifiers, TTL driver output, cable ends, shutter delays) should be done in software and be configurable in the `ddb`.\n\nWe need an example how to do configurable delay compensation for TTL (rising and falling edges independently), DDS, and DAC outputs. Latencies will be in the ns-µs range but the required compensation may be negative. The case of a TTL-shutter with several ms latency might be a bit tricky because of the required headroom of the rtio counter w.r.t. `now` but also educationally interesting in demonstating \"how to alter the past\".\n\n(c.f. #36 for a DDS latency contribution)\n"},"comment":{"url":"https://api.github.com/repos/m-labs/artiq/issues/comments/307341337","html_url":"https://github.com/m-labs/artiq/issues/40#issuecomment-307341337","issue_url":"https://api.github.com/repos/m-labs/artiq/issues/40","id":307341337,"user":{"login":"jordens","id":1338946,"avatar_url":"https://avatars2.githubusercontent.com/u/1338946?v=3","gravatar_id":"","url":"https://api.github.com/users/jordens","html_url":"https://github.com/jordens","followers_url":"https://api.github.com/users/jordens/followers","following_url":"https://api.github.com/users/jordens/following{/other_user}","gists_url":"https://api.github.com/users/jordens/gists{/gist_id}","starred_url":"https://api.github.com/users/jordens/starred{/owner}{/repo}","subscriptions_url":"https://api.github.com/users/jordens/subscriptions","organizations_url":"https://api.github.com/users/jordens/orgs","repos_url":"https://api.github.com/users/jordens/repos","events_url":"https://api.github.com/users/jordens/events{/privacy}","received_events_url":"https://api.github.com/users/jordens/received_events","type":"User","site_admin":false},"created_at":"2017-06-09T09:25:16Z","updated_at":"2017-06-09T09:25:16Z","body":"That's the scheme we would advocate as well. It would just be nice to have examples and some skeleton code that shows how it can be implemented."}}
{"actor":{"display_login":"jordens"}}