Abstract: A monitor device includes a packet communication device, a report data transmitting device, a communication status determination device, and a transmission error history storage device. The report data transmitting device transmits report data for reporting an error of a broadcast radio wave retransmission system to an external monitoring center through the packet communication device. The communication status determination device determines whether or not transmission of the report data is successfully performed by the report data transmitting device. The transmission error history storage device stores an error in the report data transmission, when the communication status determination device determines that an error occurs in transmission of the report data, as a transmission error history in a storage device.

Abstract: A monitor device includes a packet communication device, a report data transmitting device, a communication status determination device, and a transmission error history storage device. The report data transmitting device transmits report data for reporting an error of a broadcast radio wave retransmission system to an external monitoring center through the packet communication device. The communication status determination device determines whether or not transmission of the report data is successfully performed by the report data transmitting device. The transmission error history storage device stores an error in the report data transmission, when the communication status determination device determines that an error occurs in transmission of the report data, as a transmission error history in a storage device.

Abstract: A theft checking system that improves detection precision of theft checking systems. A micrometer samples data of received signals for three periods of a swept signal. A signal analyzer confirms signals that are regarded as resonance signals occurring in each of the first half and the second half of the first period, ignoring noise signals, and determines only whether similar signals corresponding to the resonance signals are present in each of the following two periods. A detection circuit recognizes the presence of the resonance signals and thereby recognizes and notifies passage of a tagged article.

Abstract: A theft checking system that improves precision in detecting a tagged article. A transmission antenna (1) transmits a signal of a constant amplitude in which sine-wave sweep is made within a range of 7.4 MHz to 8.9 MHz at 140 Hz. A reception side is provided with a signal analyzing portion (9) that predicts from the occurrence timing of a signal received within the first half period of a period of the sweep, the occurrence timing of a signal to be received within the second half period, and that compares a received signal with the predicted timing and, if it is confirmed that the signals are in an opposite phase relationship, recognizes passage of the article.

Abstract: A theft checking system that improves precision in detecting a tag and prevents false notification. A first computer (S3) samples a waveform in a fixed length of time of a signal received by a reception antenna. A digital direct synthesizer (S4) divides the sampled waveform data of the fixed length of time and a reference signal pre-registered in a memory circuit of a calculating portion respectively into portions by equal pitch with respect to the time axis, multiplies the value of the reference signal at each point separately by the value at each point in the data corresponding to that point, and calculates the sum of the products. A matching circuit (S6) compares the calculated value with a predetermined value to detect a waveform that agrees with the reference oscillation. A tag (S7) actuates notifying means.