DWC disconnects but only whilst printing

[digimatic]

I have a strange (and recent issue).

DWC keeps disconnecting (regardles of client I connect from) but only whilst printing. (see below)

I don't think this is a network issue as duet2 doesn't report any network disconnects and if I run a constant ping in the background I get 0% packet loss, even at the same time the web client is disconnecting

Other things (such as a gcode transfer are never interrupted) and if the printer isn't printing it almost never occurs.

Version 3.4.0

It has only recently started to occur, most recently I upgraded paneldue to 3.4, but have made another few changes such as enabling a servo on duex.pwm5 (on my duex5 board) for a wiper and configuring pressure advance. but it's hard to see how these changes would have caused it. Are there any particular diagnostics I should look at?

eg. 05/08/2022, 14:30:59 Connection established
05/08/2022, 14:30:58 Connection interrupted, attempting to reconnect...
Operation failed (Reason: Service Unavailable)
05/08/2022, 14:29:29 Connection established
05/08/2022, 14:29:28 Connection interrupted, attempting to reconnect...
Operation failed (Reason: Service Unavailable)
05/08/2022, 14:29:24 Connection established
05/08/2022, 14:29:24 Connection interrupted, attempting to reconnect...
Operation failed (Reason: Service Unavailable)
05/08/2022, 14:29:04 Connection established
05/08/2022, 14:29:03 Connection interrupted, attempting to reconnect...
Operation failed (Reason: Service Unavailable)

[Phaedrux]

Please try 3.4.1

What browser are you using?

What Duet board? SBC mode? Wired or wireless?

[digimatic]

@phaedrux

Sorry should have said, Duet2/Duex5.

Browser, mostly use Firefox on a Mac, but have the same issue with Safari, and Firefox on Linux

[Phaedrux]

Can you open the developer console of your browser when you have the disconnections and show us what it shows?

[Notepad]

It could be EMI interference mixed with a bug. I have personally had some issues where a micro stutter causes the WebOS to drop (the bug I think causes the WebOS to stay stuck in the connection interrupted loop), and after taking the printer to an EMC lab, it apparently is because of the motor wires / motors interfering with the Wi-Fi signals.

its a bit annoying because the motors were from E3D, but apparently the motor wire length they supply is the perfect length to interfere with wireless devices. The thing that worked for me was to shorten the motor wires, as previously I just zip tied the entire length in a circle, which probably didn't help at all.

[digimatic]

@phaedrux

Sorry for the delay.

When it happens I am getting a 503 from the API

Tried turning the console refresh down to 1000ms as the default of 250 seemed excessive. But issue still exists.

[digimatic]

@notepad

Oh now that is interesting as I recently added another stepper and a servo for a wiper solution, and thinking about it I don't think I had this problem before then.

There is no reason for either to be powered whilst printing, so I'll try adding something to power them down and see if that makes a difference.

[dc42]

@digimatic what do you have the microstepping set to (M350 in config.g)? Setting microstepping too high can cause the available CPU time to be taken up by generating step pulses when moving at speed, resulting in the web server getting too little CPU time. We recommend x16 with interpolation enabled for most machines, except that extruders with low steps/mm (e.g. 100 at x16 microstepping) can benefit from x32.

[digimatic]

@dc42

I have everything set to x16 microstepping and interpolation, other than the coupler that has the interpolation disabled in the default E3D provided config)

M350 E16:16:16:16 I1
M350 C16 I10
M350 X16 Y16 Z16 I1

C being the coupler (this is an E3D Toolchanger)

Recently I added:
M350 A16 I1

A axis being the height adjustment stepper for my Pebble Wiper

[engikeneer]

@digimatic Is yours a Duet2 wifi or ethernet?
I have had something similar happen on my e3d toolchanger with a Duet ethernet. It appears to temporarily drop connection to DWC when the XY motors are moving, so I had assumed EMI of some sort.

I also have a paneldue attached but that seems to be okay...

[dc42]

@digimatic please upgrade to release 3.4.2rc2 in case the bug fixes in the wifi and Ethernet code in that release are relevant to this issue.

If the issue persists, please post a M122 report.

[digimatic]

@dc42

Updated to 3.4.2rc2. Updated DWC and the Wifi server as well just to be sure. Problem still persists.

M122 causes my machine to reset with no output to console beforehand (tried telnet and via DWC) . Sorry how am I supposed to use M122 ?

Also reinforcing either interference or too busy microstepping. Call me crazy but the disconnects seem to happen very much around the time of a layer change. (I don't have the slicer inserting any gcode for layer transitions)

[digimatic]

But moving Z for example when not printing doesn't.

[droftarts]

@digimatic Check if your SD card is causing the problem; see https://docs.duet3d.com/en/User_manual/RepRapFirmware/SD_card#troubleshooting-sd-card-issues

Ian

[Phaedrux]

@digimatic said in DWC disconnects but only whilst printing:

M122 causes my machine to reset with no output to console beforehand

Are you sure you didn't send M112 by mistake? That will perform a reset.

EDIT: Actually, you may have been affected by this bug: https://forum.duet3d.com/topic/29577/m122-causes-reset-on-3-4-2-rc2?_=1660415932643

[digimatic]

@droftarts

SD card checks out ok, also the 500 errors I get shouldn't be requiring reglular loads from SD, I'd say SD failure is more likely to impact loading the site pages themselves not the API server, looking at the code.

[digimatic]

@phaedrux

Yes it is that bug, thanks I'll try the fixed build in pastebin so i can get the M122 output.

[dc42]

@digimatic said in DWC disconnects but only whilst printing:

M122 causes my machine to reset

There is a bug in the Duet 2 builds of RRF that causes this. See https://forum.duet3d.com/post/292098 for fixed binaries.