Duet 0.85 randomly disconnecting

I'm running a duet 0.8.5 (dc42's 1.09m firrmware) from my iMac, connecting via MatterControl. I don't have a good way to connect the ethernet on the Duet, so I'm stuck with USB for now. I'm running Parallels with a windows VM, so it shows me whenever a new USB device is detected, and this dialog shows up when it stops printing.

It's been working OK for most of the day (after fixing a firmware problem yesterday) until about an hour ago. I'm now getting random USB disconnects in mid-print. The print stops, and the terminal view in MC doesn't show anything but a "lost connection" message. I have an 'always on' fan, and I don't hear it drop at all as if the power supply were twitching. I've tried a different USB cable.

Also had it stop once when using the manual controls to move the head out of the way of a previously failed print. hit Y+ a couple times, then X+ a couple more, then it froze again.

Any suggestions on what to check?

TIA

Brian

Some suggestions:

1. Is the Duet resetting when the USB port disconnects? To check, on reconnection run M122 and look in the output for the last reset time and reason, to see of the last reset was when the print started or when the USB disconnected.

2. If it is resetting, what is the last reset reason (and the reset code, if it was a software reset), given in the M122 output?

3. A common cause of spurious resets in 3D printers is transients on the ground loop formed when you connect a PC to a 3D printer over USB. To reduce the risk of a reset:

- Power the computer and the printer and nothing else from the same AC mains distribution block

- Use a USB cable with a ferrite bead on it

However, I suggest you connect over Ethernet instead. If your iMac has an Ethernet port, you can use a cable. If not and you have a WiFi network, you can use a Ethernet-to-WiFi bridge such as the TPLink WR710N.

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Large delta printer [miscsolutions.wordpress.com], E3D tool changer, Robotdigg SCARA printer, Crane Quad and Ormerod

Disclosure: I design Duet electronics and work on RepRapFirmware, [duet3d.com].

i think i've found the issue. i'm running off a recycled atx power supply, which has a little light on it which AFAICT is on when it's working properly. if i watch that light and the extruder heater LED, they go out at approximately the same time. so what i think is happening is that the 12v is dropping just enough to reset the usb (as well as causing a VERY frequent ajax error in the web interface). heading out how to replace the power supply, will post if i can get better results.

brian

p.s. - usb cable already had a core on it. i'll investigate the potential for ground loop issues as well... although that'll be harder to solve, as i've got lots of stuff that needs to be plugged in.

yep, was entirely due to an old, weak power supply. haven't had a single usb fault since installing the new one. still get an AJAX error almost every time I go to look at the web page, but ...

Quote
blindahl
yep, was entirely due to an old, weak power supply. haven't had a single usb fault since installing the new one. still get an AJAX error almost every time I go to look at the web page, but ...

Any particular ajax error?

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Large delta printer [miscsolutions.wordpress.com], E3D tool changer, Robotdigg SCARA printer, Crane Quad and Ormerod

Disclosure: I design Duet electronics and work on RepRapFirmware, [duet3d.com].

I'm just getting a generic dialog, like:

Communication Error

An AJAX error was reported, so the current session has been terminated.

Please check if your printer is still on and try to connect again.

Don't know if it's related but I 'm also getting the following pretty often (surely each time I power up the duet):

Could not establish connection to the Duet firmware!
Please check your settings and try again.

The developer console shows these:

GET [192.168.10.x] /fonts/glyphicons-halflings-regular.woff2 
jquery-2.1.3.min.js:4 GET [192.168.10.x] /language.xml 500 (too few command words)
jquery-2.1.3.min.js:4 XHR finished loading: GET "http://192.168.10.x/language.xml".
jquery-2.1.3.min.js:4 GET [192.168.10.x] /rr_connect?password=reprap 500 (too few command words)
jquery-2.1.3.min.js:4 XHR finished loading: GET "http://192.168.10.x/rr_connect?password=xxxx".

Reloading the page does not help. The only thing that helps is using another browser. This connects w/out problems and then connecting with the former browser works fine (until this happens again). Note that it doesn't matter which browser is used first and which is used second (Chrome+Firefox)...

I think this started happening after upgrading the web interface to DWC v1.07.

Edited 3 time(s). Last edit at 12/11/2015 12:28PM by mandrav.

mandrav, next time this problem occurs, please connect Pronterface and enable webserver debugging by sending M111 S1 P2. Then try to connect again. The commands received by the web server will be echoed to Pronterface, and you can compare them with the ones that the developer console shows as having been sent. The "too few command words" error suggests that not all the message has been received by the web server.

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Large delta printer [miscsolutions.wordpress.com], E3D tool changer, Robotdigg SCARA printer, Crane Quad and Ormerod

Disclosure: I design Duet electronics and work on RepRapFirmware, [duet3d.com].

I suspect this problem may be related to too long cookies being sent to the Duet as part of HTTP requests. Fortunately 1pennyshort informed me that there is now a better way to store configuration parameters in the web browser (in detail that's HTML5's localStorage), so I'll drop cookies in my next DWC release and use that instead. I hope this will eventually eliminate this kind of connection problems.

Chris -

Let me know if you need any testing on this. I'm VERY tired of the continuous resets that are happening.

brian

p.s. what's the best place for bug reports & feature requests? your github? i've got several things that have come to mind whilst watching things print.

Edited 1 time(s). Last edit at 12/17/2015 01:40PM by blindahl.

If it helps, I'm getting that same ajax error on my laptop while setting up the Duet 0.8.5

Linux Mint 17.3
FireFox 42.0
Firmware Version: 1.09m-dc42 (2015-12-08)
Web Interface Version: HTML: 1.07, JS: 1.07

If DWC 1.07 is sending over long cookies, perhaps you should go back to DWC 1.06.

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Large delta printer [miscsolutions.wordpress.com], E3D tool changer, Robotdigg SCARA printer, Crane Quad and Ormerod

Disclosure: I design Duet electronics and work on RepRapFirmware, [duet3d.com].