Yes, that may be the case. The only thing I'm a bit worried about now is what will happen if the router gets powerless or reboots. Will it assign the same IP-addresses to the devices? I guess there's no guaranty for that, but hopefully that will not happen so often. Maybe I should restrict the DHCP-range in the router to just cover two IP-adresses, as there are only these two measurment devices on the network.