{"action":"created","issue":{"url":"https://api.github.com/repos/MarlinFirmware/Marlin/issues/2125","labels_url":"https://api.github.com/repos/MarlinFirmware/Marlin/issues/2125/labels{/name}","comments_url":"https://api.github.com/repos/MarlinFirmware/Marlin/issues/2125/comments","events_url":"https://api.github.com/repos/MarlinFirmware/Marlin/issues/2125/events","html_url":"https://github.com/MarlinFirmware/Marlin/issues/2125","id":78027272,"number":2125,"title":"Synchronized vs unsynchronized commands","user":{"login":"alexrj","id":594957,"avatar_url":"https://avatars.githubusercontent.com/u/594957?v=3","gravatar_id":"","url":"https://api.github.com/users/alexrj","html_url":"https://github.com/alexrj","followers_url":"https://api.github.com/users/alexrj/followers","following_url":"https://api.github.com/users/alexrj/following{/other_user}","gists_url":"https://api.github.com/users/alexrj/gists{/gist_id}","starred_url":"https://api.github.com/users/alexrj/starred{/owner}{/repo}","subscriptions_url":"https://api.github.com/users/alexrj/subscriptions","organizations_url":"https://api.github.com/users/alexrj/orgs","repos_url":"https://api.github.com/users/alexrj/repos","events_url":"https://api.github.com/users/alexrj/events{/privacy}","received_events_url":"https://api.github.com/users/alexrj/received_events","type":"User","site_admin":false},"labels":[],"state":"open","locked":false,"assignee":null,"milestone":null,"comments":14,"created_at":"2015-05-19T10:20:55Z","updated_at":"2015-05-20T08:57:12Z","closed_at":null,"body":"Hello!\r\nIs there any documentation about what commands are synchronized/buffered and which ones are executed immediately?\r\n\r\nI see a lot of confusion about that point. The [documentation for M400](http://www.marlinfirmware.org/index.php/M400) states:\r\n\r\n    This command should rarely be needed since non-movement commands should already wait, \r\n    but M400 can be useful as a workaround for badly-behaved commands.\r\n\r\nBut looking at the code most of the non-movement commands such as `M104`, `M106`, `M42`, `M280` don't call `st_synchronize()` thus appear to be executed immediately (well, as soon as the command buffer is processed but not waiting the motion queue to be finished).\r\n\r\nIn this GitHub issue tracker I found several conflicting statements about `M106` being synchronized and not.\r\n\r\nWhat's the situation? Can this be documented clearly? Thank you! :)"},"comment":{"url":"https://api.github.com/repos/MarlinFirmware/Marlin/issues/comments/103815292","html_url":"https://github.com/MarlinFirmware/Marlin/issues/2125#issuecomment-103815292","issue_url":"https://api.github.com/repos/MarlinFirmware/Marlin/issues/2125","id":103815292,"user":{"login":"AnHardt","id":211931,"avatar_url":"https://avatars.githubusercontent.com/u/211931?v=3","gravatar_id":"","url":"https://api.github.com/users/AnHardt","html_url":"https://github.com/AnHardt","followers_url":"https://api.github.com/users/AnHardt/followers","following_url":"https://api.github.com/users/AnHardt/following{/other_user}","gists_url":"https://api.github.com/users/AnHardt/gists{/gist_id}","starred_url":"https://api.github.com/users/AnHardt/starred{/owner}{/repo}","subscriptions_url":"https://api.github.com/users/AnHardt/subscriptions","organizations_url":"https://api.github.com/users/AnHardt/orgs","repos_url":"https://api.github.com/users/AnHardt/repos","events_url":"https://api.github.com/users/AnHardt/events{/privacy}","received_events_url":"https://api.github.com/users/AnHardt/received_events","type":"User","site_admin":false},"created_at":"2015-05-20T08:57:12Z","updated_at":"2015-05-20T08:57:12Z","body":"Maybe M104 is not the perfect example. Until the temperature will begin to rise an average G1 is history anyway.\r\nMore interesting, to me, is the question how a change affecting movements is handled. Changing the acceleration for example. Will this alter the behavior of already planed moves?"}}