Abstract: A data transfer system for transferring a transfer frame including a plurality of character codes representing a numeral of numerical data to be transferred, error detection data including a parity code for the character codes and a predetermined transfer control code to a controller on a receiver side from a controller on a sender side. In the controller on the sender side, a parity code obtained for the character codes is divided into a plurality of bit groups, a predetermined code which does not coincide with the predetermined transfer control code is affixed to each divided bit group to form divided parity data having a specific number of bits, and the transfer frame is constituted with these plural divided parity data as the error detection data. In the controller on the receiver side, the original parity code is restored from a plurality of divided parity data in the received transfer frame and is used.

Abstract: A meter at each user's house has a bar-coded user number shown thereon, and has a display section for displaying a reading. A data input terminal unit has a bar code reader for reading the user number and a keyboard for manually inputting a present reading. A data recording controller has a meter reading data file having a present reading for each user number. The data input terminal unit radio-transmits a read user number to the data recording controller and radio-receives a previous reading, corresponding to the user number, from said data recording controller. The data input terminal unit computes the amount used from this previous reading and the present reading manually input, and causes a printer to print meter reading data including this used amount on a reading slip while radio-transmitting it to the data recording controller.

Abstract: A casing of a portable data input/transmission apparatus has an end portion, the size of which is determined such that the end portion can be held by one hand. A pen-scanner type bar code reader for reading a bar code is attached to one end of the casing in the longitudinal direction. A keyboard for enabling at least numerical data to be input is attached near the other end of the casing in the longitudinal direction. A transmitter/receiver is stored within the casing, the transmitter/receiver being designed to output wirelessly to an external data processing apparatus code data read by the bar code reader and at least numerical data input from the keyboard. A pair of antenna-containing grooves are formed in a pair of facing side surfaces extending in the longitudinal direction of the casing, such that the grooves extend in the longitudinal direction of the casing to said other end of the casing.

Abstract: A portable data input apparatus comprises an elongated casing. A pen-scanner type bar code reader reads a bar code provided according to the kind of a commodity, and outputs a corresponding code data unit. A keyboard is designed to input at least a numerical data unit representative of the amount of the commodity. A display device displays the code data unit and the numerical data unit. A display mode changing circuit is designed to invert the image of the data units displayed on the display device in the vertical direction and the horizontal direction, in response to a detection signal, which is output when the code data and numerical data are inversely displayed.

Abstract: A measuring device having a transmitter includes a measuring device section, a data processing unit, a transmitter, and a casing. The measuring device section converts measuring data into a digital value and outputs it. The data processing unit arranges the measurement data obtained in the measuring device section in a transmission data string having a predetermined format and outputs it. The transmitter transmits the transmission data, which is output from the data processing unit, by radio transmission. The transmitter is housed in the casing, which is attached to a portion near an operation section of the measuring device section, together with the data processing unit. An antenna output terminal of the transmitter is connected to the casing or a conductor portion near the casing.

Abstract: A host apparatus collects the physical or chemical quantities of articles, which have been measured by a plurality of measuring devices, for example, vernier calipers. Each calipers has a caliper unit as a measuring means, a dip-switch, a CPU, a RAM, and a transmitter. The caliper unit has an analog-to-digital (A/D) converter. The dip-switch is operated, thus setting an ID number of the device, before the device is used. The ID number is stored into the RAM. When the transmission button of the device is pushed, the CPU edits the digital value supplied from A/D converter and the ID number stored in the RAM, thereby forming a serial-data message. This message is transmitted by a transmitter, in the form of a radio message. The host apparatus has a receiver and a host computer. The receiver received the serial-data messages transmitted from the measuring devices.

Abstract: A caliper unit has a connector having connecting terminals. The caliper unit measures a value of a product, and generates digital data representing this value. A data-transmitting apparatus has a housing. The housing can be attached to caliper unit. The housing has a fastening ring and a connecting plug. The plug can be connected to the connector of the caliper unit by the fastening ring. A microcomputer including a CPU is provided within the housing. A RAM is also provided within the housing, for storing the digital data input from the caliper unit and also an identification (ID) number assigned to the data-transmitting apparatus. The microcomputer forms a serial-data message from the digital data and the ID number, both stored in the RAM. A transmitter is provided within the housing, for transmitting the serial-data message in the form of a radio message.

Abstract: The analog data representing a value measured of a product by means of a measuring device such as a vernier calipers is converted into digital data by an analog-to-digital converter. A CPU incorporates the digital data into a data message. The CPU is driven by a clock signal output from a quartz crystal oscillator. A first frequency divider divides the clock signal, thus generating a signal of a first frequency, and a second frequency divider divides the clock signal, thereby generating a signal of a second frequency. During the duration of each digital data signal at the "0" (low) level, the CPU generates a signal at the "low" or "high" level, in accordance with the signal generated by the first frequency divider. Similarly, during the duration of each digital data signal at the "1" (high) level, the CPU generates a signal at the "low" or "high" level, in accordance with the signal generated by the second frequency divider. The signals generated by the CPU are supplied to a transmitter.

Abstract: A data communication system comprising a master station and n number of substations, each substation comprising a receiving photocoupler and a transmission photocoupler, and wherein a particular substation may be connected into a transmission line leading to the master station by connecting the receiving photocoupler in series in parallel circuit to the transmission line and wherein data transmission from the master station to the substation is accomplished by means of a current supplied forward with respect to the receiving photocoupler of the substation, and data transmission from the substation to the master station is done by means of a current supplied reverse with respect to the transmission photocoupler of the substation.

Abstract: A redundancy system for data communications upon two duplicate communication channels, each having transmission and reception circuits, characterized by a switching circuit for selecting one of said two communication channels, a single error detection circuit for detecting an error in the signal transmitted, and a control circuit for the switching circuit arranged to cause said two communication channels to alternately transmit signals when both the channels are in normal operation, and to cause one of said two channels to be selected when the other fails. The two channels share the error detection circuit and the control circuit and can therefore be built at a reduced cost and operated efficiently. Since the two channels are regularly checked for errors, they are operated with increased reliability.