New DuetEthernet connection problems
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As a resume of everything that I have tested related to LAN connection issues that I have observed:
- It always happens after an automatic reboot requested by, for example, a change of the config.g file.
- When it happens, the board no longer replies to PING, although it is a static IP and the router doesn't warn of any conflicts (the board is set as 192.168.1.200, DHCP range is .160-.191, all devices are below .160 except for some starting with .250.
- Connecting over USB and issuing M552 S0 followed by M552 S1 doesn't really bring back the connectivity. After M552 S1 I always waiting for the confirmation of the IP.
- Most of the times connectivity is available again after 15-20 minutes of not touching the board.
- During all these tests there is no "mechanical" interference with the board (touching LAN cable, moving things around, trying to re-plug the cable etc.).
- Sometimes, after M552 S1, the board is briefly available for 10-15s, like getting to the list of files in the /sys directory, and dies again when trying to open one of them.
- LAN connector LEDs are properly active during all this time!
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If connectivity is restored after 20 minutes, that sounds like either an issue with router or other network devices, or an intermittent fault on the Duet Ethernet. If you connect the Duet directly to a PC or laptop using an Ethernet cable (you may need to use a crossover cable), does it work reliably?
Do the LEDs on the Ethernet socket of the Duet behave normally?
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I will do tomorrow this test. As my PCs all have Gigabit ports, crossover cables should not be needed, normally!
The LEDs behave normally, but those are pretty low level (physical layer!, not aware of IP related problems, if any). And that brings me to the next potential problem - what if the Ethernet adapter is not properly programmed with the IP and whatever is also needed? Is there a way to check? Does the firmware any checks before reporting the status after M552 S1?Just while writing this message I decided to remove the Ethernet adapter from the Dues and check for poor solder joints, none found so that is good news. But why is the outer shield of the RJ45 connector connected to pin signal no. 8? On my board there is a HanRun HR911105A RJ45 connector with magnetics. That connector is designed for 100Mbps connections and pin 8 is internally connected to ground through a 75Ohm resistor and a 1000pF capacitor. Connecting it to GND may have unexpected effects on a 1Gbps network (my entire network is wired for 1Gbps, using FTP cables, thus having huge GND loops!). While this a non-issue for 100Mbps network switches/routers, I wonder what do the user with complaints have in their networks! As a side note, tomorrow I will test with a simple UTP cable.
Just saw that this is the reference design for the WIZnet 5500 chip. I'm more used to Gigabit magnetics! -
Just wanted to report back saying that I got everything running again in DWC 1.20 and DE firmware 1.21 RC2. I wiped the sys folder after backing it up and recreated my config.g file from scratch using the online tool. I must've done something strange in my configuration that caused it to no longer connect.
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Not all network cables are equal…
While I had the issues with the DuetEthernet I tried using several cables from the same batch. All of them successfully used with Gigabit capable devices (PCs, laptops etc.) and showing full transfer speeds. Today I had to connect, after a very long period of time, a 10/100Mbps only device and, to my surprise, I had the same issues that I have observed with the Duet. So I have looked through the pile of junk that I have around and found several more devices with only 10/100Mbps networking and found the same problem.
Luckily I also found around a cable from a different batch and now all the networking problems are gone.
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I'm glad you both solved the problems. I've never heard of cables working ai 1Gb/sec but not at 100Mb/sec before!
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Do you want a couple of "samples"?
The Windows/Linux devices that I used for further tests always properly negotiated the IP address with the DHCP server but they could not get even one reply from the DNS. So things are way weirder than I could even imagine. Most probably they will end up being recycled so I don't waste precious time when testing/using other devices not capable of Gigabit.
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if you are in the UK then a sample would be good; otherwise the postage cost will get silly.
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Sorry for the delay, but I had two rather long days!
Unfortunately I'm just few thousands km to the East of UK so shipping is way more than what's worth paying for a set of poor network cables. But I'm mainly a radio guy (professionally doing things like software radio and related to that) so I have a little bit of equipment here. So I decided to get the big guns into the battle.
A quick frequency characteristic of the cables, good vs poor ones, showed rather poor behaviour at low frequencies for the unusable ones. As Gigabit PHYs are a lot more advanced than 10/100Mbps ones, I presume they were able to overcome the problem, just!
But poor frequency characteristic in the lower frequency range usually indicates a fault in the copper wires. After a few bending cycles here and there and the cracks in the copper turned into actual breaks and the cables are now, a few of them, unusable no matter the network type. Most probably it was a problem with the batch of cable from the manufacturer, but trying to deeply understand a 50EUR problem, spending several days, is beyond any commercial reasoning so the whole batch will go for recycling!
All I can say for sure is the outer jacket of the cable showed no signs of mechanical abuse, either by pinching or pulling, so it might have been a batch of cable that was "good enough" during the factory tests, but useless after bending it a couple of times.
P.S. It was the only time I have bought ready-made network cables!
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Thanks for the update. I use flat cat6 network cables purchased inexpensively on ebay. No problems with them so far and they are very flexible.
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I presume UTP and not FTP or STP!
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Yes, UTP in particular these http://www.ebay.co.uk/cln/kenable_ltd/FLAT-CAT6-Gigabit-Network-Cables/89021312013.
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As I do a lot of radio monitoring stuff (hardware, software) even my keyboard and mouse are wired. And UTP cables tend to be quite noisy so everything in here is FTP or STP. Unfortunately that comes with a lot more rigidity if keeping the costs within reasonable limits!
