DWC freezes

deckingman

Just noticed this. I'm 6 hrs into a longish print and a couple of times I've noticed that the DWC display has stopped updating any of the displayed parameters. If I disconnect, then reconnect, it catches up just as if I had closed the tab and opened it again. There is nothing untoward reported in the G-Code Console. I'm using Firefox and Win7. It's no big deal but would be nice to fix it if I can.

dc42

Can you confirm that you are running firmware 1.15 and DWC 1.12?

A Wireshark trace would be helpful.

roboduet

The same thing for me, but I think it depends on WiFi network load. I will try to dump logs using Wireshark.

Firmware Name: RepRapFirmware for Duet WiFi
Firmware Version: 1.15e (2016-10-02)
WiFi Server Version: 1.02
Web Interface Version: 1.12

deckingman

Firmware as above. i.e. 1.15e (2-16-10-02), WiFi 1.02, Web 1.12. No idea what Wireshark is or how to use it so I'll leave that for roboduet.

roboduet

Just caught this (or similar) issue. DWC interface isn't updating temperatures at all, no periodic JSON status requests both in Firefox developer panel and in Wireshark, but DWC is still able to execute user-initiated commands (homing, macroses and so on). No information provided in log panel of DWC after executing commands. For example, after issuing M122 no debug information shown in log, but if I issue G28 - printer homes correctly. Seems like /rr_reply request isn't queued.

Also no AJAX errors and so on in log panel, DWC just stopped doing any periodic tasks.

Another (new) tab with DWC in the same browser is working as expected.

dc42

Try opening the debug console, which will usually appear if you press control-shift-J. If DWC isn't sending status requests, it usually means that there has been a JavaScript exception, which will be recorded in the console.

roboduet

No exceptions or other errors are recorded in FF dev console, no errors in DWC log and DWC isn't sending status requests. But I opened console just after I realized that DWC is frozen again. Maybe something is happened before.

Console is still open, so I can dump internal variables or other info that you may be interested in.

roboduet

Caught this again with both FF dev console logs and Wireshark logs.

Wireshark:

Instead of this "standard" packet sequence (> = from PC to Duet, < = from Duet to PC):

[[language]]
> SYN
< SYN, ACK
> ACK
> GET /rr_status?type=1
< HTTP/1.1 200 OK
> FIN, ACK
< RST, ACK

Wireshark recorded the following sequence

[[language]]
< SSDP "NOTIFY * HTTP/1.1" request (NT: upnp:rootdevice, NTS: ssdp:alive)

> SYN
< SYN, ACK
> ACK
> GET /rr_status?type=1
< ACK
> FIN, ACK
< RST, ACK

Take attention to SSDP request and to empty /rr_status request body.

Browser side console log:

[[language]]
"GET /rr_status?type=1" - successful request
"GET /rr_status?type=1" - request with empty response
"GET /" - I don't know why JS requests / index page after unsuccessful requst

After last GET / nothing happens. GET / caused by JS request, I have call stack and other info.

roboduet

One more catch:

Browser side:

[[language]]
"GET /rr_status?type=1" - successful request (req1)
"GET /rr_status?type=1" - successful request according to Wireshark, but 200 OK empty request for browser (req2)
"GET /" - again, JS requests index page (/) after failure

Wireshark side:
req1 (successful):

[[language]]
GET /rr_status?type=1 HTTP/1.1
Host: 192.168.0.28
User-Agent: Mozilla/5.0 (Windows NT 10.0; WOW64; rv:49.0) Gecko/20100101 Firefox/49.0
Accept: application/json, text/javascript, */*; q=0.01
Accept-Language: en-US,en;q=0.5
Accept-Encoding: gzip, deflate
X-Requested-With: XMLHttpRequest
Referer: http://192.168.0.28/
DNT: 1
Connection: keep-alive

HTTP/1.1 200 OK
Cache-Control: no-cache, no-store, must-revalidate
Pragma: no-cache
Expires: 0
Content-Type: application/json
Content-Length: 387
Connection: close

{"status":"I","coords":{"axesHomed":[0,0,0],"extr":[0.0],"xyz":[0.00,0.00,0.00]},"currentTool":0,"params":{"atxPower":0,"fanPercent":[0.00,100.00,0.00],"speedFactor":100.00,"extrFactors":[100.00]},"seq":1204,"sensors":{"probeValue":0,"fanRPM":0},"temps":{"bed":{"current":26.6,"active":0.0,"state":2},"heads":{"current":[25.8],"active":[0.0],"standby":[0.0],"state":[2]}},"time":26601.2}

req2 (shown with 200 OK status but with empty response body):

[[language]]
GET /rr_status?type=1 HTTP/1.1
Host: 192.168.0.28
User-Agent: Mozilla/5.0 (Windows NT 10.0; WOW64; rv:49.0) Gecko/20100101 Firefox/49.0
Accept: application/json, text/javascript, */*; q=0.01
Accept-Language: en-US,en;q=0.5
Accept-Encoding: gzip, deflate
X-Requested-With: XMLHttpRequest
Referer: http://192.168.0.28/
DNT: 1
Connection: keep-alive

HTTP/1.1 200 OK
Cache-Control: no-cache, no-store, must-revalidate
Pragma: no-cache
Expires: 0
Content-Type: application/json
Content-Length: 387
Connection: close

{"status":"I","coords":{"axesHomed":[0,0,0],"extr":[0.0],"xyz":[0.00,0.00,0.00]},"currentTool":0,"params":{"atxPower":0,"fanPercent":[0.00,100.00,0.00],"speedFactor":100.00,"extrFactors":[100.00]},"seq":1204,"sensors":{"probeValue":0,"fanRPM":0},"temps":{"bed":{"current":26.7,"active":0.0,"state":2},"heads":{"current":[25.8],"active":[0.0],"standby":[0.0],"state":[2]}},"time":26601.9}

The only thing I can understand at this moment that DWC requests index page (/) if it receives empty AJAX response and after this stops any further requests.