Active-type contactless information storage device for storing sensor detected values

A machine-readable storage medium storing a program thereon for use in an active-type contactless storage device which is assessable from a reader and writer device, the active-type contactless storage device comprising:

• a memory which stores information including an identification;
• a timer which measures time;
• a battery which supplies electric power at least to the timer;
• a receiver unit which senses a carrier of an information request signal at a first frequency from the reader and writer device;
• a transmitter unit which modulates a carrier with data and transmits a response signal at a second frequency to the reader and writer device;
• a sensor unit which detects a physical quantity or state and then holds corresponding detected data;
• and
• a remaining power detector unit which detects a remaining power of the battery, the program being operable to causing the active-type contactless storage device to execute:
• causing, in a sleep period of time which occurs intermittently, the sensor unit, the memory and the remaining power detector unit to be in an inactive state;
• determining an operation mode for the sensor unit in accordance with the remaining power of the battery detected by the remaining power detector unit;
• causing, in accordance with the determined operation mode, the receiver unit, the sensor unit or the remaining power detector unit to operate at a particular timing;
• causing the sensor unit to detect a physical quantity or state and then hold corresponding detected data;
• causing, in accordance with the determined operation mode;
• the memory to store the detected data from the sensor unit;
• controlling the receiver unit to sense a carrier of an RF signal at the first frequency in a carrier sensing period of time;
• and
• in response to detection by the receiver unit of a carrier of an RF signal at the first frequency in a particular carrier sensing period of time, causing the receiver unit to further receive an information request signal, and then causing, in response to the received information request signal, the transmitter unit to transmit a response signal at the second frequency carrying the data in the memory.