Software bundle 3.4.0 beta 4 released
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@owend the main purpose of the datetime function is that it allows you to make datetime values persistent by constructing a command to reload a previously saved datetime value into a variable.
The datum is currently 1 Jan 1970 but we will likely change it because year 2038 is looming.
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@dc42 - our chamber heaters are still faulting when heating up the first time with the following error. We have verified this is does not happen when rolling back to 3.3.
Error: Heater 2 fault: temperature rising much more slowly than the expected 2.4°C/sec
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@oozebot 2.4C/sec sounds very high for a chamber heater. I suspect you haven't tuned it or set manual M307 parameters.
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@dc42 I started another thread about this. No, we have never been able to get tuning to complete for our chamber heaters, and our M307 is not optimized, but it worked previously. If you have a minute and could weigh in on the other thread with some mock tuning suggestions, we'd be all ears! Thanks
https://forum.duet3d.com/topic/25099/6hc-3-4b3-chamber-heater-faults
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@oozebot what M307 parameters are you using for your chamber heater?
You may need to reduce the R parameter and/or increase the D parameter.
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@dc42 Thanks - whatever was fixed with heater faults in 3.4 exposed the issue and we've suspected it was a configuration issue. After a quick review, I think the missing R value is the culprit. It has been added and we are now performing additional testing.
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@dc42 - we are still consistently getting chamber heater faults with 3.4 beta when heating from room temp. I've lowered R to 0.1, jacked the C value up to 30 minutes, set D to the maximum of 350 and it still happens!
Error: Heater 2 fault: temperature rising much more slowly than the expected 0.1°C/sec
I think what's happening is the new fault protection that was added in 3.4 is not allowing the temp to swing negative - which can and does happen when the chamber initially heats.
Are there any other M307 variations you'd like us to test? We really need to get this resolved before the release of 3.4 stable. Thanks
config.g
;== Enclosure Heater ========================= M308 S2 P"temp1" Y"thermistor" T100000 B3950 M950 H2 C"0.out2" T2 M307 H2 B1 C1800 D350 R0.1 M141 H2
Edit - we are still working on this to see if it's our settings. This just happened - we have R set to .5 but got a fault that it was rising slower than .2c?
9/29/2021, 11:37:03 AM Error: Heater 2 fault: temperature rising much more slowly than the expected 0.2°C/sec 9/29/2021, 11:34:44 AM m307 h2 Heater 2 model: heating rate 0.500, cooling time constant 140.0, dead time 5.50, max PWM 1.00, calibration voltage 0.0, mode bang-bang
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@oozebot your M307 D parameter looks far to low for a chamber heater to me. Try 20 or 30.
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@dc42 - with D set to 20, it faulted within the first minute:
9/30/2021, 7:33:36 AM m307 h2 Heater 2 model: heating rate 0.500, cooling time constant 1800.0, dead time 20.00, max PWM 1.00, calibration voltage 0.0, mode bang-bang 9/30/2021, 7:33:01 AM Error: Heater 2 fault: temperature rising much more slowly than the expected 0.5°C/sec
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@oozebot can you post a screen shot of the temperature graph between turning it on and when it faults?
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It doesn't really show anything. With D20, it faults after 20 seconds as the temp hasn't had a chance to rise at all. At D350, it will at least have ~10 minutes to start warming up. Usually, with D350, after clearing the fault, it will then make it up to target temp.
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@dc42 I just set
R=0.01, which it surprisingly allowed, and it's still going with D20. I'll let it run and report back, but again, before 3.4b, we never had these issues. Thanks** second edit ** R.02 is the minimum allowed. My mistake - cooling a test machine down and re-running the test.
it just faulted:
Error: Heater 2 fault: temperature rising much more slowly than the expected -0.0°C/sec
Cooling it back down and then rerunning with D350. Will report back afterwards.
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@dc42 - please take a minute to watch the video linked below. It contains two chamber faults.
The first is with M307 H2 B1 D30 R1 and happens at 1:18.
The second is with M307 H2 B1 D30 R0.02 and happens at 8:57.Thanks
https://www.dropbox.com/s/djkj53ksuj2q2re/proto - Google Chrome 2021-09-30 11-33-52.mp4?dl=0
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@dc42 - bumping this up. David - will you please review my last post above and the video I posted? Is there anything else we can try to get around this issue? We understand/believe this is the result of a bug fix, but it is negatively impacting chamber heaters due to the way the temp bounces around before it stabilizes.
Unfortunately, this is a breaking change for us and is getting a lot of attention on our end. Thank you
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We've finally found a combination that is working:
M307 H2 B1 C1800 D350 R.02
If anyone has any suggestions, we'd be all ears about how to better tune chamber heaters as we have not been able to get auto-tuning to finish. Or does it really matter? We are leaning towards it not mattering.. Thanks