Abstract: To suppress power consumption when product information is not received from a server apparatus. A transmission section (302) of an electronic shelf label (300-1) transmits a registration request signal to the server apparatus. A transmission interval determining section (308) extends a transmission interval of the registration request signal in a stepwise manner in accordance with a time length of an asynchronous state in which a response signal is not received in response to the registration request signal from the server apparatus. A terminal state request signal generating section (305) generates a terminal state request signal making a request to another electronic shelf label that terminal state information be transmitted, and the transmission section (302) transmits the generated terminal state request signal. After receiving the terminal state request signal, the another electronic shelf label transmits the terminal state information.

Abstract: A system for collection of data and entry of the data to a host computer has a portable, hand held, data collector for collecting data and a stationary data relay for receiving the data from the data collector and for transmitting the data to the host computer. The portable hand held data collector includes a case of a size and shape to be held by one hand during use, a keyboard for inputting the data, displaying for displaying the data, memory for storing the data and an interface for transmitting the data to external. The data relay includes a case shaped to set the portable data collector thereon, of first interface for receiving the data transmitted from the data collector and of said interface for comunicating bidirectionally to the host computer.