If you read closely in the Conext Gateway User's Guide, under features, there is a vague reference to an included 8Gbyte MicroSD card ... Used for keeping statistics. There is no other mention of using it. Since our Gateway is in a weather-tight shed, I had to scratch some old brain cells to recall a "Do not remove" label on the side of the box.
Once I removed the Gateway from the shed and temporarily moved its xanbus terminator plug to the end of the cable, a closer look revealed two such labels, on opposite sides of the box. This Gateway had gone out of warranty 4 months ago, so nothing to lose, so peeled off the label tape. Sure enough, one covered a (rather recessed) MicroSD, the other, a set of 6 pins.
I guessed what the pins were, so I went all the way and used a Torx screwdriver to open the box and read the PC board labels for those pins to identify Ground, RX, & TX data. From another project, I had a 3.3v serial to USB cable to attach from these pins to my PC. Powered the Gateway up with its 12vdc power brick, and I could instantly see the "u-boot" code listing off the interfaces and routines to bring it active. Useful info, but in the end, not required for the fix.
So then turned my attention to the MicroSD. You know the stuff you read that SD card memory bits can only function 10s of thousands of time before they fail? That means you should never use them for logging a couple of dozen register values every minute of every day, because even if the SD controller chip is reallocating good mem blocks in place of bad ones, it's gonna run out in a couple of years.
To remove the 8GB SD, you push it in with your fingertip till it clicks, then it pops out further so you can grab it.
I first figured I would try to recover/copy it to a new MicroSD with Linux disk tools. Well although Linux "sees" the sdx device there, the clowns at schneider decided to make it unreadable as any filesystem partition supported by my linux.
I went back and tried booting the Gateway with no card. But u-boot showed several messages about missing pieces. It was on one of these that I used the DHCP assigned IP to first try https, no luck. Then telnet, yes, but as mentioned before in this thread no user / pw would work.
Well, then found the fix. Inserted a new, Sandisk 32GB card into the Gateway and fired it up again... It spent a looong time at the "access the SD card" in the U-boot step... Reformatting?? Yes, I think so!
Low and behold, the GUI came up on Ethernet DHCP assigned IP. But you have to go back and use the default new user/pw and reconfigure the Gateway.
I used a 32GB MicroSD because that was all I had handy. Does that mean it will last 4x as long as the 8GB? I have no idea. I would however not try using larger than 32GB because there might be something like the old FAT 32 partition support limit. And just to take the research one step further... I tried mounting that "reformatted" 32GB drive in several OS's and again, they would not recognize it.
I have the feeling, everyone with the Conext Gateway model is going to run into this over time... Why couldn't the Insight Local app warn you? My guess is schneider would be happy to sell you a $700US+ InsightFacility box.
Unfortunately, I have been very busy trying to help a cousin recover her home after severe flooding in her area over the summer months, and haven't participated in this forum the way I would like. But I will try to reply to any questions as soon as I can.