To prevent a loss of a memory storing information for maintenance of an object of maintenance, and an intrusion of a fluid into an enclosure of the object of maintenance, to take measures for radio wave interference by the object of maintenance, and allow lightening protection.
By disposing an IC memory 25 of an RF tag 20 as a memory device in an enclosure of a control instrument 10, its loss is prevented, and the enclosure is sealed by utilizing an antenna 21 of the RF tag 20. The antenna 21 is attached to the exterior of the enclosure so as to exchange radio waves with the exterior of the enclosure and is connected to the interior by a conducting wire insulated with the enclosure of which interior is sealed. Or a part of the metal enclosure is formed in a lid-like shape, and information for maintenance is exchanged by removing the metal lid, meeting the VCCI standard. Furthermore, by disposing an antenna 16 in correspondence 14 with an RE tag on the side of the control instrument 10, the RF tag 20 can be in the state where it is electrically insulated with a control circuit of the control instrument 10.
Shuichi Fukuda
Takashi Sasaki