{"action":"created","issue":{"url":"https://api.github.com/repos/MarlinFirmware/Marlin/issues/2066","labels_url":"https://api.github.com/repos/MarlinFirmware/Marlin/issues/2066/labels{/name}","comments_url":"https://api.github.com/repos/MarlinFirmware/Marlin/issues/2066/comments","events_url":"https://api.github.com/repos/MarlinFirmware/Marlin/issues/2066/events","html_url":"https://github.com/MarlinFirmware/Marlin/issues/2066","id":75683677,"number":2066,"title":"Thermistors malfunction tests results","user":{"login":"clefranc","id":4294448,"avatar_url":"https://avatars.githubusercontent.com/u/4294448?v=3","gravatar_id":"","url":"https://api.github.com/users/clefranc","html_url":"https://github.com/clefranc","followers_url":"https://api.github.com/users/clefranc/followers","following_url":"https://api.github.com/users/clefranc/following{/other_user}","gists_url":"https://api.github.com/users/clefranc/gists{/gist_id}","starred_url":"https://api.github.com/users/clefranc/starred{/owner}{/repo}","subscriptions_url":"https://api.github.com/users/clefranc/subscriptions","organizations_url":"https://api.github.com/users/clefranc/orgs","repos_url":"https://api.github.com/users/clefranc/repos","events_url":"https://api.github.com/users/clefranc/events{/privacy}","received_events_url":"https://api.github.com/users/clefranc/received_events","type":"User","site_admin":false},"labels":[{"url":"https://api.github.com/repos/MarlinFirmware/Marlin/labels/Improvement","name":"Improvement","color":"009800"},{"url":"https://api.github.com/repos/MarlinFirmware/Marlin/labels/Needs%20more%20work","name":"Needs more work","color":"fbca04"}],"state":"open","locked":false,"assignee":null,"milestone":null,"comments":13,"created_at":"2015-05-12T17:53:29Z","updated_at":"2015-05-13T11:47:13Z","closed_at":null,"body":"Here are the bed and hotend thermistors malfunction tests results.\r\n\r\nTests done using full thermal protection.\r\n\r\nPlease report errors, omissions, ask for more tests or information about results here.\r\n\r\n**EDIT 2015-05-13 - Added PR to each test**\r\n\r\n### TEST 1 - Bed's thermistor disconnected before startup ###\r\n**PR :** https://github.com/MarlinFirmware/Marlin/pull/2055\r\n\r\nThe bed shows 0°C current temperature at startup.\r\n\r\n**Host:**\r\n* The bed doesn't appears in the Manual Control tab!\r\n* Sending a M140 S100 sets the bed's target tempeature to 100°C on the LCD...\r\n* The bed is not heating...\r\n* No warning or error displays on the console.\r\n\r\n**LCD:**\r\n* Going to the Prepare/Preaheat ABS/Preheat ABS Bed set the bed target temperature to 100°C on the LCD...\r\n* Idem to host\r\n\r\n**Conclusion:**\r\nWhen the bed's thermistor is disconnected before startup, the bed's current temperature displayed on the LCD is always 0°C. When sending M140 command, or using LCD preheat, the bed's target temperature displayed on the LCD is 100°C. The bed is not heating and there is no warning or error displayed. The bed heating resumes normally after reconnecting the thermistor.\r\n\r\n### THERMAL RUNAWAY RISK: none ###\r\n---\r\n### TEST 2 - Bed's thermistor disconnected before startup AND thermistor table begins at 25°C ###\r\n**PR :** https://github.com/MarlinFirmware/Marlin/pull/2055\r\n\r\nThe bed shows 25°C current temperature at startup.\r\n\r\n**Host:**\r\n* Sending a M140 S100 sets the bed's target tempeature to 100°C on the LCD...\r\n* The bed starts heating...\r\n* The bed's current temperature stays at 25°C...\r\n* The bed continues to heat indefinitively...\r\n\r\n**LCD:**\r\n* Going to the Prepare/Preaheat ABS/Preheat ABS Bed set the bed target temperature to 100°C on the LCD...\r\n* Idem to host.\r\n\r\n**Conclusion:**\r\nWhen the bed's thermistor is disconnected before startup AND thermistor table begins at 25°C, the bed's current temperature displayed on the LCD is always 25°C. When sending M140 command, or using LCD preheat, the bed's target temperature displayed on the LCD is 100°C. The bed will heat indefinitively, or stops when proper command sent.\r\n\r\n### THERMAL RUNAWAY RISK: HIGH ###\r\n---\r\n### TEST 3 - Bed's thermistor disconnected after heating begins ###\r\n**PR :** https://github.com/MarlinFirmware/Marlin/pull/2055\r\n\r\nThe bed shows 25°C current temperature at startup.\r\n\r\n**Host:**\r\n* Sending a M140 S100 sets the bed's target tempeature to 100°C on the LCD...\r\n* The bed starts heating...\r\n* The bed's thermistor is disconnected...\r\n* The bed's current temperature drops to 0°C...\r\n* The bed's target temperature stays at 100°C...\r\n* The bed stops heating immediately...\r\n* No warning or error displays on the console.\r\n\r\n**LCD:**\r\n* Going to the Prepare/Preaheat ABS/Preheat ABS Bed set the bed target temperature to 100°C on the LCD...\r\n* Idem to host.\r\n\r\n**Conclusion:**\r\nWhen the bed's thermistor is disconnected after heating begins, the bed's current temperature displayed on the LCD drops to 0°C and its target temperature remains at 100°C. The bed stops heating and there is no warning or error displayed. The bed heating resumes normally after reconnecting the thermistor.\r\n\r\n### THERMAL RUNAWAY RISK: none ###\r\n---\r\n### TEST 4 - Bed's thermistor disconnected after heating begins AND thermistor table begins at 25°C ###\r\n**PR :** https://github.com/MarlinFirmware/Marlin/pull/2055\r\n\r\nThe bed shows 25°C current temperature at startup.\r\n\r\n**Host:**\r\n* Sending a M140 S100 sets the bed's target tempeature to 100°C on the LCD...\r\n* The bed starts heating and current temperature is rising...\r\n* The bed's thermistor is disconnected...\r\n* The bed's current temperature drops to 25°C...\r\n* The bed's target temperature stays at 100°C...\r\n* The bed continues to heat indefinitively...\r\n* No warning or error displays on the console.\r\n\r\n**LCD:**\r\n* Going to the Prepare/Preaheat ABS/Preheat ABS Bed set the bed target temperature to 100°C on the LCD...\r\n* Idem to host.\r\n\r\n**Conclusion:**\r\nWhen the bed's thermistor is disconnected after heating begins AND thermistor table begins at 25°C, the bed's current temperature displayed on the LCD drops to 25°C and its target temperature remains at 100°C. The bed will heat indefinitively, or stops when proper command sent.\r\n\r\n### THERMAL RUNAWAY RISK: HIGH ###\r\n---\r\n### TEST 5 - Bed's thermistor disconnected after target temperature reached ###\r\n**PR :** https://github.com/MarlinFirmware/Marlin/pull/2055\r\n\r\nThe bed shows 25°C current temperature at startup.\r\n\r\n**Host:**\r\n* Sending a M190 S100 sets the bed's target tempeature to 100°C on the LCD...\r\n* The LCD status message shows **Bed Heating.**\r\n* The bed starts heating...\r\n* The bed's current temperature reaches 100°C...\r\n* The LCD status message shows **Bed done.**\r\n* The bed's thermistor is disconnected...\r\n* The bed's current temperature drops to 0°C...\r\n* The bed's target temperature remains at 100°C...\r\n* The bed stops heating immediately...\r\n* No warning or error displays on the console.\r\n\r\n**LCD:**\r\n* Going to the Prepare/Preaheat ABS/Preheat ABS Bed set the bed target temperature to 100°C on the LCD...\r\n* Idem to host.\r\n\r\n**Conclusion:**\r\nWhen the bed's thermistor is disconnected after target temperature is reached, the bed's current temperature drops to 0°C and its target temperature remains at 100°C. The bed heating stops immediately. There is no warning or error displayed when the thermistor is disconnected. The bed heating resumes normally after reconnecting the thermistor.\r\n\r\n### THERMAL RUNAWAY RISK: none ###\r\n---\r\n### TEST 6 - Bed's thermistor disconnected after target temperature reached AND thermistor table begins at 25°C ###\r\n**PR :** https://github.com/MarlinFirmware/Marlin/pull/2055\r\n\r\nThe bed shows 25°C current temperature at startup.\r\n\r\n**Host:**\r\n* Sending a M190 S100 sets the bed's target tempeature to 100°C on the LCD...\r\n* The LCD status message shows **Bed Heating.**\r\n* The bed starts heating...\r\n* The bed's current temperature reaches 100°C...\r\n* The LCD status message shows **Bed done.**\r\n* The bed's thermistor is disconnected...\r\n* The bed’s current temperature drops to 25°C...\r\n* The bed continues to heat indefinitively...\r\n* No warning or error displays on the console.\r\n\r\n**LCD:**\r\n* Going to the Prepare/Preaheat ABS/Preheat ABS Bed set the bed's target temperature to 100°C on the LCD...\r\n* Idem to host.\r\n\r\n**Conclusion:**\r\nWhen the bed's thermistor is disconnected after target temperature is reached AND thermistor table begins at 25°C, the current temperature displayed on the LCD drops to 25°C. The bed will heat indefinitively, or stops when proper command sent.\r\n\r\n### THERMAL RUNAWAY RISK: HIGH ###\r\n---\r\n### TEST 7 - Hotend's thermistor disconnected before startup ###\r\n**PR :** https://github.com/MarlinFirmware/Marlin/pull/2055\r\n\r\nThe hotend shows 0°C current temperature at startup. The LCD status message shows **Err: MINTEMP**\r\n\r\n**Host:**\r\n* Sending a M104 S240 don’t sets the hotend's target tempeature to 240°C on the LCD...\r\n* The hotend’s target temperature stays at 0°C…\r\n* The hotend’s current temperature stays at 0°C…\r\n* The hotend is not heating...\r\n\r\n**LCD:**\r\n* Going to the Prepare/Preaheat ABS/Preheat ABS 1 don’t set the hotend's target temperature to 240°C and bed's at 100°C...\r\n* The hotend and bed target temperature stays at 0°C…\r\n* The hotend’s current temperature stays at 0°C…\r\n* The hotend and bed are not heating...\r\n\r\n**Conclusion:**\r\nWhen the hotend's thermistor is disconnected before startup, the hotend's current temperature displayed on the LCD is always 0°C. When sending M104 command, or using LCD preheat, the hotend will not heat. New hotend’s target temperature and heating operates normally after the thermistor reconnection. The LCD status message shows **Err: MINTEMP** even after the hotend’s thermistor is reconnected or new commands sent.\r\n\r\n### THERMAL RUNAWAY RISK: none ###\r\n---\r\n### TEST 8 - Hotend's thermistor disconnected before startup AND thermistor table begins at 25°C ###\r\n**PR :** https://github.com/MarlinFirmware/Marlin/pull/2055\r\n\r\nThe hotend shows 25°C current temperature at startup.\r\n\r\n**Host:**\r\n* Sending a M104 S240 sets the hotend's target tempeature to 240°C on the LCD...\r\n* The hotend starts heating...\r\n* Hotend's current temperature stays at 25°C...\r\n* The hotend's target temperature drops to 0°C after the 16 seconds mark...\r\n* The hotend stops heating...\r\n* LCD status message shows **parameters:**\r\n\r\n**LCD:**\r\n* Going to the Prepare/Preaheat ABS/Preheat ABS 1 set the hotend's target temperature to 240°C and bed's at 100°C...\r\n* The hotend and bed starts heating...\r\n* Hotend's current temperature stays at 25°C, bed is rising...\r\n* The hotend and bed target temperature are set to 0°C after the 16 seconds mark...\r\n* The hotend and bed stops heating (cooling fan still on)...\r\n* LCD status message shows **parameters:**\r\n\r\n**Conclusion:**\r\nWhen the hotend's thermistor is disconnected before startup AND thermistor table begins at 25°C, the hotend's current temperature displayed on the LCD is always 25°C. When sending M104 command, or using LCD preheat, the hotend will heat until 16 seconds elapsed then all heaters are shutdown properly. The LCD status message **parameters:** is then displayed.\r\n\r\n### THERMAL RUNAWAY RISK: none ###\r\n---\r\n### TEST 9 - Hotend's thermistor disconnected after heating begins AND before 16 seconds elapsed ###\r\n**PR :** https://github.com/MarlinFirmware/Marlin/pull/2055\r\n\r\nThe hotend shows 25°C current temperature at startup.\r\n \r\n**Host:**\r\n* Sending a M104 S240 sets the hotend's target tempeature to 240°C on the LCD...\r\n* The hotend starts heating...\r\n* The hotend’s current temperature is rising…\r\n* The hotend’s thermistor is disconnected before 16 seconds mark…\r\n* The hotend stops heating immediately...\r\n* LCD status message shows **Err: MINTEMP**.\r\n\r\n**LCD:**\r\n* Going to the Prepare/Preaheat ABS/Preheat ABS 1 don’t set the hotend's target temperature to 240°C and bed's at 100°C...\r\n* Idem to host.\r\n\r\n**Conclusion:**\r\nWhen the hotend's thermistor is disconnected after heating begins AND before 16 seconds elapsed, the hotend's current temperature displayed on the LCD drops to 0°C and the hotend’s stops heating. New hotend’s target temperature and heating operates normally after the thermistor reconnection. The LCD status message shows **Err: MINTEMP** even after the hotend’s thermistor is reconnected or new commands sent.\r\n\r\n### THERMAL RUNAWAY RISK: none ###\r\n---\r\n### TEST 10 - Hotend's thermistor disconnected after heating begins AND before 16 seconds elapsed AND thermistor table begins at 25°C ###\r\n**PR :** https://github.com/MarlinFirmware/Marlin/pull/2055\r\n\r\nThe hotend shows 25°C current temperature at startup.\r\n\r\n**Host:**\r\n* Sending a M104 S240 sets the hotend's target tempeature to 240°C on the LCD...\r\n* The hotend starts heating and current temperature is rising...\r\n* The hotend's thermistor is disconnected BEFORE 16 seconds elapsed...\r\n* The hotend's current temperature drops to 25°C...\r\n* The hotend's target temperature is set to 0°C at the the 16 seconds mark...\r\n* The hotend stops heating...\r\n* LCD status message shows **parameters:**\r\n\r\n**LCD:**\r\n* Going to the Prepare/Preaheat ABS/Preheat ABS Bed set the hotend's target temperature to 240°C and bed's to 100°C on the LCD...\r\n* The hotend and bed starts heating...\r\n* The hotend's thermistor is disconnected BEFORE 16 seconds elapsed...\r\n* The hotend's current temperature drops to 25°C...\r\n* The hotend and bed target temperature drops to 0°C at the the 16 seconds mark...\r\n* The hotend and bed stops heating (cooling fan still on)...\r\n* LCD status message shows **parameters:**\r\n\r\n**Conclusion:**\r\nWhen the hotend's thermistor is disconnected after heating begins AND before 16 seconds elapsed AND thermistor table begins at 25°C, the hotend's current temperature displayed on the LCD drops to 25°C. The hotend and bed stops heating at the the 16 seconds mark. The LCD status message **parameters:** is then displayed.\r\n\r\n### THERMAL RUNAWAY RISK: none ###\r\n---\r\n### TEST 11 - Hotend's thermistor disconnected after heating begins AND after 16 seconds elapsed ###\r\n**PR :** https://github.com/MarlinFirmware/Marlin/pull/2055\r\n\r\nThe hotend shows 25°C current temperature at startup.\r\n \r\n**Host:**\r\n* Sending a M104 S240 sets the hotend's target tempeature to 240°C on the LCD...\r\n* The hotend starts heating...\r\n* The hotend’s current temperature is rising…\r\n* The hotend’s thermistor is disconnected after 16 seconds mark…\r\n* The hotend stops heating immediately...\r\n* LCD status message shows **Err: MINTEMP**.\r\n\r\n**LCD:**\r\n* Going to the Prepare/Preaheat ABS/Preheat ABS 1 don’t set the hotend's target temperature to 240°C and bed's at 100°C...\r\n* Idem to host.\r\n\r\n**Conclusion:**\r\nWhen the hotend's thermistor is disconnected after heating begins AND after 16 seconds elapsed, the hotend's current temperature displayed on the LCD drops to 0°C and the hotend’s stops heating. New hotend’s target temperature and heating operates normally after the thermistor reconnection. The LCD status message shows **Err: MINTEMP** even after the hotend’s thermistor is reconnected or new commands sent.\r\n\r\n### THERMAL RUNAWAY RISK: none ###\r\n---\r\n### TEST 12 - Hotend's thermistor disconnected after heating begins AND after 16 seconds elapsed AND thermistor table begins at 25°C ###\r\n**PR :** https://github.com/MarlinFirmware/Marlin/pull/2055\r\n\r\nThe hotend shows 25°C current temperature at startup.\r\n\r\n**Host:**\r\n* Sending a M104 S240 set the hotend's target tempeature to 240°C on the LCD...\r\n* The hotend starts heating and current temperature is rising...\r\n* The hotend's thermistor is disconnected after 16 seconds elapsed...\r\n* The hotend's current temperature drops to 25°C...\r\n* The hotend continues to heat indefinitively...\r\n* After 60 seconds, hotend still heating...\r\n\r\n**LCD:**\r\n* Going to the Prepare/Preaheat ABS/Preheat ABS Bed set the hotend's target temperature to 240°C and bed's to 100°C on the LCD...\r\n* Idem to host.\r\n\r\n**Conclusion:**\r\nWhen the hotend's thermistor is disconnected after heating begins AND after 16 seconds elapsed AND thermistor table begins at 25°C, the current temperature displayed on the LCD drops to 25°C. The hotend will heat indefinitively, or stop when proper command sent.\r\n\r\n### THERMAL RUNAWAY RISK: HIGH ###\r\n---\r\n### TEST 13 - Hotend's thermistor disconnected after target temperature reached ###\r\n**PR :** https://github.com/MarlinFirmware/Marlin/pull/2055\r\n\r\nThe hotend shows 25°C current temperature at startup.\r\n\r\n**Host:**\r\n* Sending a M109 S240 set the hotend's target tempeature to 240°C on the LCD...\r\n* The LCD status message shows **Heating…**\r\n* The hotend starts heating and current temperature is rising...\r\n* The hotend's current temperature reaches 240°C...\r\n* The LCD status message shows **Heating done.**\r\n* The hotend's thermistor is disconnected...\r\n* The hotend's current temperature drops to 0°C...\r\n* The hotend's target temperature drops to 0°C...\r\n* The hotend stops heating immediately...\r\n* LCD status message shows **Err: MINTEMP**.\r\n\r\n**LCD:**\r\n* Going to the Prepare/Preaheat ABS/Preheat ABS Bed set the hotend's target temperature to 240°C and bed's to 100°C on the LCD...\r\n* Idem to host.\r\n\r\n**Conclusion:**\r\nWhen the hotend's thermistor is disconnected after target temperature is reached, the hotend's current temperature displayed on the LCD drops to 0°C and the hotend’s stops heating. New hotend’s target temperature and heating operates normally after thermistor reconnection. The LCD status message shows **Err: MINTEMP** even after the hotend’s thermistor is reconnected or new commands sent.\r\n\r\n### THERMAL RUNAWAY RISK: none ###\r\n---\r\n### TEST 14 - Hotend's thermistor disconnected after target temperature reached AND thermistor table begins at 25°C ###\r\n**PR :** https://github.com/MarlinFirmware/Marlin/pull/2055\r\n\r\nThe hotend shows 25°C current temperature at startup.\r\n\r\n**Host:**\r\n* Sending a M109 S240 set the hotend's target tempeature to 240°C on the LCD...\r\n* The LCD status message shows **Heating…**\r\n* The hotend starts heating and current temperature is rising...\r\n* The hotend's current temperature reaches 240°C...\r\n* The LCD status message shows **Heating done.**\r\n* The hotend's thermistor is disconnected...\r\n* The hotend's current temperature drops to 25°C...\r\n* The hotend's target temperature remains at 240°C...\r\n* The hotend continues to heat indefinitively...\r\n\r\n**LCD:**\r\n* Going to the Prepare/Preaheat ABS/Preheat ABS Bed set the hotend's target temperature to 240°C and bed's to 100°C on the LCD...\r\n* Idem to host.\r\n\r\n**Conclusion:**\r\nWhen the hotend's thermistor is disconnected after its target temperature is reached AND thermistor table begins at 25°C, the hotend's current temperature displayed on the LCD drops to 25°C and its target temperature remains at 240°C. The hotend will heat indefinitively, or stop when proper command sent.\r\n\r\n### THERMAL RUNAWAY RISK: HIGH ###\r\n---\r\nSee https://github.com/MarlinFirmware/Marlin/issues/2024 and https://github.com/MarlinFirmware/Marlin/issues/2025 for original issues.\r\n\r\n"},"comment":{"url":"https://api.github.com/repos/MarlinFirmware/Marlin/issues/comments/101637118","html_url":"https://github.com/MarlinFirmware/Marlin/issues/2066#issuecomment-101637118","issue_url":"https://api.github.com/repos/MarlinFirmware/Marlin/issues/2066","id":101637118,"user":{"login":"nophead","id":566149,"avatar_url":"https://avatars.githubusercontent.com/u/566149?v=3","gravatar_id":"","url":"https://api.github.com/users/nophead","html_url":"https://github.com/nophead","followers_url":"https://api.github.com/users/nophead/followers","following_url":"https://api.github.com/users/nophead/following{/other_user}","gists_url":"https://api.github.com/users/nophead/gists{/gist_id}","starred_url":"https://api.github.com/users/nophead/starred{/owner}{/repo}","subscriptions_url":"https://api.github.com/users/nophead/subscriptions","organizations_url":"https://api.github.com/users/nophead/orgs","repos_url":"https://api.github.com/users/nophead/repos","events_url":"https://api.github.com/users/nophead/events{/privacy}","received_events_url":"https://api.github.com/users/nophead/received_events","type":"User","site_admin":false},"created_at":"2015-05-13T11:47:12Z","updated_at":"2015-05-13T11:47:12Z","body":"Well the algorithm I proposed earlier is simpler and catches all those simply by insisting it should get hotter when full on and cooler when full off.  Sudden jumps will get caught indirectly if they violate those basic rules. Catching them immediately will get lots of false alarms due to noisy wiring, poor grounds and loose connections. People would rather their print finished with a loose connection than abort and as long as the temperature is still under control that is OK. \r\n"}}