The problem was that the "Smart Updater 2.0" tool lost the connection to the scanner during the update. When I retried the software wanted me to enter my serial number, but then it said that no settings backup was found. The Hokuyo support told me to enter the number without the trailing "A", but this also didn't help. They also told me that the backup file is stored under:
C:/Users/<username>/AppData/Local/Hokuyo Automation Co,LTD/Smart Updater/<serialnumber>.ust_backupI noticed that the filename was my serial number without the trailing "A" but also without the leading "H". So I entered only the numbers into the Smart Updater dialog and the updated started again.
Still the updated process didn't work. It seems like on every reboot of the Hokuyo during the update process, windows or the Hokuyo is unable to reconnect (The ethernet device is shown as "cable disconnected"). After replugging the ethernet cable the connection is established again.
So I used the ultimate counter intuitive trick for firmware updates ever:
I unplugged and replugged the cable during the update!
Every time the "Connection" dialog with the green infinite loading bar appeared I waited for 3 seconds and then unplugged and replugged the cable. Sometimes the process just continues but sometimes some error messages appear. Just click them away and wait. The update still continues!
With this technique I was able to update from 2.17 to 2.19 and then to 2.21. It seems that update 2.19 partly fixed the reconnect issue, because after some reboots the reconnect work but I still had to unplug once to make the whole process work.
I used a Windows 8.1 notebook with its IP set to 192.168.0.1 directly connected to the Hokuyo's with its IP set to 192.168.0.10 before update. Perhaps the static IPs and/or windows 8.1 lead to this problem. I haven't tried the update in a DHCP setup with other Windows versions yet.
For now the laser works again with the UrgBenriPlus tool and the ROS node. But somehow the webinterface stopped working...
Update:
I just got a response from an Hokuyo engineer regarding my story:
First of all, good to know the ".ust_backup" was actually there and that you finally upgraded your sensor.
There is an old problem with all UST-**LX that the encoding symbol ("A") at the end of the serial number (printed in the sensor label) is never configured on the firmware. The customer reads from the label "H*******A" and types the same text in the SmartUpdater but the sensor will refuse because it doesn't understand the final letter. The future versions of the firmware update script ("*.ust") will fix this issue.
As to the unplug/replug trick of the Ethernet cable during the update process, the old 2.17/2.19 firmwares had a bug causing it to use different MAC addresses in normal mode and during updating mode. Windows does not react well with MAC address changes on the fly so the solution is to flush the ARP table. For that run the following command on the command prompt:
arp -d
unplugging/replugging the Ethernet cable also works because the sensor sends a gratuitous ARP message informing its current IP address every time the cable is replugged. Anyway that problem was correctly fixed on version 2.21. Also we will try to add a troubleshooting section in our web page detailing this and other issues.
Finally, regarding the web interface, it was an experimental/non-documented/not-fully-tested functionality we decided to drop. So from 2.19 it is not operational. Good thing you explored thoroughly the sensor capabilities beyond what is written.
So you can just execute "arp -d" in your console instead of re-plugging the cable!
