René's URL Explorer Experiment

{"@context":"https://schema.org","@type":"DiscussionForumPosting","headline":"slcan interface needs some time-tweaking (Possible solution provided)","articleBody":"### Describe the bug\r\nMessages are truncated while using send command.\r\nMessages are truncated while using close command.\r\n\r\n\r\n### To Reproduce\r\nCode as example. Requires python-can and pyserial modules.\r\nWindows PC and CANable with original firmware: https://github.com/normaldotcom/canable-fw\r\nCounter-interface: PCAN USB dongle and oscilloscoop\r\n\r\nProblem 1: When looping messages within the \"with can.Bus\", one can see on the scope that the messages are corrupted/truncated.\r\nProblem 2: When looping messages main, one can see that the last message in the \"with can.Bus\" is truncated.\r\n\r\nPossible solution:\r\nEnd the _write-function with: \"time.sleep(3.0e-5)\"\r\nBegin the close-function with: \"time.sleep(3.0e-5)\"\r\n\r\nAdditional information, experimentally obtained:\r\n10kbps: total fail (!)\r\n20kpbs: requires 5.0e-3 seconds\r\n50kpbs: requires 2.0e-3 seconds\r\n83kpbs: requires 2.0e-3 seconds\r\n100kpbs: requires 6.0e-4 seconds\r\n125kpbs: requires 6.0e-4 seconds\r\n250kpbs: requires 5.0e-5 seconds\r\n500kpbs: requires 3.0e-5 seconds\r\n750kpbs: other side (PCAN in this case) has no setting for 750, it has 800 which is not compatible\r\n1000kpbs: requires 4.0e-6 seconds or even lower\r\n\r\n### Expected behavior\r\nTruncated messages: seen on a oscilloscoop. PCAN viewer tels me stuffing errors. The error will result in resending infinite retrying messages.\r\n\r\n### Additional context\r\nOS and version: Windows 11\r\nPython version: Python 3.12\r\npython-can version: 4.3.1\r\npyserial version: 3.5\r\npython-can interface/s (if applicable): slcan\r\nHardware interface: CANable 2.0 Pro\r\nIDE: PyCharm recent version\r\nOscilloscope: Rigol DS1000-series\r\nCounter-interface: PCAN USB isolated version and PCAN-View software\r\n\r\n\u003c!-- Add any other context about the problem here. --\u003e\r\nPossible solution:\r\nEnd the _write-function with: \"time.sleep(3.0e-5)\"\r\nBegin the close-function with: \"time.sleep(3.0e-5)\"\r\n\r\n\u003cdetails\u003e\r\n\u003csummary\u003eTraceback and logs\u003c/summary\u003e\r\n\u003c!-- Has to be followed by an empty line! --\u003e\r\nNone\r\n\r\n\u003c!-- More details such as a minimal script to demonstrate the bug, relevant logs and any tracebacks go here. --\u003e\r\nSee code example.\r\n\r\n\u003c!-- Code examples can be included: --\u003e\r\n```\r\ndef send_one():\r\n    with can.Bus(interface=\"slcan\", channel=\"COM7@115200\",  bitrate=500000, sleep_after_open=0.0) as bus:\r\n        msg = can.Message(\r\n            arbitration_id=0x555, data=[0x55, 0x55, 0x55, 0x55, 0x55, 0x55, 0x55, 0x55], is_extended_id=False\r\n        )\r\n\r\n        try:\r\n            j = 0\r\n            while j \u003c 2:\r\n                bus.send(msg)\r\n                j = j + 1\r\n        except can.CanError:\r\n            print(\"Message NOT sent\")\r\n\r\n\r\nif __name__ == \"__main__\":\r\n    i = 0\r\n    while i \u003c 2:\r\n        send_one()\r\n        i = i + 1\r\n```\r\n\r\n\u003c/details\u003e\r\n","author":{"url":"https://github.com/Dubbels17","@type":"Person","name":"Dubbels17"},"datePublished":"2024-02-22T13:14:23.000Z","interactionStatistic":{"@type":"InteractionCounter","interactionType":"https://schema.org/CommentAction","userInteractionCount":0},"url":"https://github.com/1746/python-can/issues/1746"}