Duet Wifi Webserver not responding

Nuvag

Tonight i printed a model and closed the webinterface windwo in the brower.
This morning i couldn't connect to the webinterface (but ping still ok), so its probably not the polling from the webinterface thats causing the issue.
The log only contains about a hundret entries "Class Network spinning", no error messages.

dc42

When you are unable to connect but able to ping, if you run M552 without parameters, does it report that the Duet is connected to your network, or not?

Nuvag

Yes, i actually included that part in my last message because i thought you would ask that

>>> M552
SENDING:M552
WiFi module is connected to access point ewl-internet.ch_40357, IP address 192.168.178.15

Nuvag

Updated Webserver to 1.21.RC1 and immediatly having an instable connection, debug log:

WiFi: fGLUE: fragmented pbuf (932!=1514)!
WiFi: GLUE: fragmented pbuf (932!=1514)!
WiFi: GLUE: fragmented pbuf (932!=1514)!
WiFi: GLUE: fragmented pbuf (932!=1514)!
[...]

When reloading the page:

Unexpected state change on socket 0
Can't send anymore
New conn on socket 0 for local port 80
HTTP connection accepted
Found responder
New conn on socket 5 for local port 80
HTTP connection accepted
Found responder
Received 330 bytes
Sending reply, file = yes
HTTP req, command words { GET / HTTP/1.1 }, parameters { }
Received 339 bytes
Sending reply, file = yes
HTTP req, command words { GET /css/dwc.css HTTP/1.1 }, parameters { }
New conn on socket 0 for local port 80
HTTP connection accepted
Found responder
Received 357 bytes
Sending reply, file = yes
HTTP req, command words { GET /js/dwc.js HTTP/1.1 }, parameters { }
WiFi: GLUE: fragmented pbuf (788!=1514)!
[...]

Still having the same issue with http://192.168.178.15/js/dwc.js

When the connection is stable there are no messages with 'WiFi: GLUE: fragmented pbuf <…>', so this might be the cause of the problem.

Edit:
Additionally there is a problem with the html in line 1708:

should be

Nuvag

Webinterface was online 6 hours without a problem then failed again.
I used Wireshark to capture the network traffic, maybe this can help fpr further analysis.

This happened in the moment the connection was lost:
https://www.dropbox.com/sh/r9zkw9id482i9z0/AAA-x0NTtIISPxijZnqTiZj0a/Wireshark_DuetWifi.PNG?dl=0
This was from Microsoft Edge Browser. So my PC sent an reset and from then on all requests to the duet wifi return a reset. This continues until the ajax retry limit is reached (i set it to 50 retries).
I found other occurences earlier where my PC closed the connection but a new one could be established without problems.

Then tried to open the webinterface in a different browser (Firefox) and got:
https://www.dropbox.com/sh/r9zkw9id482i9z0/AADPnonPL1ApvNZzF8qBnV-Va/Wireshark_DuetWifi_2.PNG?dl=0

I suspect for some reason all available sockets from the wifi module in the duet to the internal modules get blocked and won't be unblocked until restarting the wifi. This would explain why the wifi connection works in general (can ping and open tcp connection) but it fails when trying to get the status report.

dc42

Thanks, I suspected that these problems might be caused by a lack of sockets. Which version of DuetWiFiServer are you using?

Nuvag

Firmware Name:
RepRapFirmware for Duet WiFi
Firmware Electronics:
Duet WiFi 1.0
Firmware Version:
1.20 (2017-12-23)
WiFi Server Version:
1.21RC1
Web Interface Version:
1.20

parovoZZ

Hi!

Is it possible to make a program reset of the Wi-Fi module on an external button? For example, execute a script:

M552 S-1;

M552 S1;

?

dc42

Yes, if you set up a trigger using M581.

T3P3Tony

if you do that I think you will need a pause in between the M552 S-1 and M552 S1 commands (I tried to make a macro for this but the S1 was executed too soon after the disable (while the wifi was still changing state) so it did not work.

parovoZZ

And then what to do?
Now I connect a USB cable during printing…...brrrrrr))))

dc42

You can insert a pause between the two M552 commands using G4.

parovoZZ

G4 is bad. Stops printing ….
Is there a NOP command?

dc42

Good point, if a print is running then G4 will wait for everything to stop. Try this:

M552 S0 ; disconnect and shutdown wifi services
M587 ; list access points, with luck this will wait for the shutdown to complete
M552 S-1
M552 S1

Danal

Another data point:

I lost connection to a DuetWifi during a long print. About six hours in. M582 (via PanelDue) stop/start did not fix. M552 stop/start and connectivity was fine.

Firmware Name: RepRapFirmware for Duet WiFi
Firmware Electronics: Duet WiFi 1.0
Firmware Version: 1.20 (2017-12-23)
WiFi Server Version: 1.20
Web Interface Version: 1.20

Wireless router is a Google WiFi mesh. It is about 15 feet from the printer. It is also true that my Desktop PC is cabled to that same Google node that serves the printer, and the wireless mesh from that node is the only connectivity available to my PC. Meaning that I'd know it instantly if the router mesh node itself dropped.

As mentioned, just another data point. No explicit reply needed.

Nuvag

As im a software developer myself i know such bugs can be hard to track down.
Some minor information which may or may not help:

wifi may fail even when the printer is not printing (turn printer on, connect webinterface, wait some time, connection lost)
wifi may fail within a few seconds after restart. Looks realy random, sometimes hours, and today it failed after <10 seconds

Its a really annoying problem, probably will finally add my PanelDue which i bought with the printer but never bothered to mount it as the wifi interface did not leave anything to be desired.

madeinta1wan

I too have lost connection. I've got long prints running (4-5 days) and am currently 'printing blind'

Is connecting through a USB a bad idea while a print is running? Is it possible to reset the wifi connection from the duet board to the router while a print is running?

Thanks,

Nate

dc42

Connecting USB while the print is running is OK if you are careful, see https://duet3d.dozuki.com/Wiki/USB_ground_loops. Yes you can reset the network interface during a print.

Have you checked the points at https://duet3d.dozuki.com/Wiki/WiFi_disconnections_and_AJAX_timeout_errors ?

EasyTarget

You should be fine with a laptop and a USB cable; You'd almost certainly be OK even if you put it on charge (laptops typically stay isolated behind their powerbrick).
Once connected You can send [c]M552 S0[/c] then [c]M552 S1[/c] to turn off/on the wifi and it /should/ reconnect to the AP, Use [c]M122[/c] to see how that works out.
I have a RasPI with a USB link to my Duet, and have had to do this several times when the Webcontrol stopped responding during a print, and it was successful each time.

madeinta1wan

That's great, thanks dc42 and EasyTarget . All sorted.

RasPi as terminal server?

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