Abstract: A method for diagnosing an IEEE 1394 home network device (6, 7) from remote is proposed. The communication between a remote testing device (2) and the IEEE 1394 home network device (6, 7) is split into two parts: between the remote testing device (2) and a gateway (4) of the home network (5) preferably TCP/IP is used as communication protocol. Inside the home network (5), i. e. between the gateway (4) and the IEEE 1394 home network device (6, 7), an IEEE 1394 low level communication protocol is used. As this IEEE 1394 low level communication protocol is common to all home network protocols employed by IEEE 1394 home network devices (6, 7), this communication method is independent of the home network protocol used by the IEEE 1394 home network devices (6, 7).

Abstract: A variable resonator is provided which comprises signal conductor 13 formed on top side surface of dielectric substrate 12, ground conductor layer 11 formed on back side surface thereof and switches 14, wherein signal conductor comprises a plurality of first conductor lines 13-1 and second conductor line 13-2 connected with all of first conductor lines, each first conductor line has a width larger than that of second conductor line to thereby a signal path through which high-frequency electric signal passes and which is longer than length of second conductor line is provided, switches 14 are connected to the ends of first conductor lines, whereby selectively opening and closing switches will electrically disconnect and interconnect interspaces between ends of first conductor lines to thereby vary length of signal path and thus change resonance frequency.