I have now had another episode like the one I described in
http://www.wxforum.net/index.php?topic=34312.msg377408#msg377408, with the WiFiLogger apparently 'dropping off the network'. This one occurred at a time when I was able to do a bit more investigation. It turned out that, notwithstanding my router having been set to assign the WiFiLogger to a specific fixed IP address, it had actually 'moved' to another address within the DHCP server's normal assignable range. After various manipulations, resetting the Logger, resetting the router, etc., I managed to get it back to its normal 'fixed' address, only to have it again switch to a different address a few hours later. I now have the Logger assigned to its correct address as a fixed address in its network settings, and it seems to be staying there, but I don't, in general, like doing things this way.
The obvious temptation would be to blame the router's DHCP server for this, but the WiFi logger is one of fifteen devices on my network which have specific IP addresses assigned in the router's DHCP settings, and it is the
only one which has ever behaved in this way (three times, now). I wonder if it is occasionally passing a 'bad' MAC address when it renews its network lease, which would cause the DHCP server to assign it a different address.
Does anyone have any useful thoughts?