A data transmission device (11; 111,) for use in a system (10) comprising a plurality of such devices is described along with a corresponding method of data transmission. A data signal (at 23) is provided for transmission and a timer apparatus (16, 18; 16, 118, 160) establishes a sequence of maximum time intervals (6 hours; 6 hours and 20 seconds) during which the data signal can be transmitted. A transmitter (18, 24, 25; 118, 24, 25) transmits the data signal during each of these maximum time i...

A control system includes receiving module for receiving a signal from a transmitting unit. Also included is a microprocessor including an input port for inputting the signal from the receiving module so as to decode the input signal and control the loads of an appliance and an output port for outputting an input control signal with respect to the input port. A signal input control section is connected between the input and output ports for directing the signal from the receiving module either t...

A sensor is disclosed which exchanges with associated data acquisition equipment a digital attribute signal, distinct from its transducer output signal, on the occurrence of a predetermined event. The invention is particularly illustrated with reference to an accelerometer which transmits sensor identification data to associated data acquisition equipment when power is first applied by using the same two signal lines as are used to provide power to the sensor and to convey the sensor output sign...

An apparatus and method are provided for performing parametric measurements using sensor transducer devices to recover frequency variant, amplitude modulated information from encoded sensory signals. A unique network is employed to achieve low-impedance current sensing in conjunction with analog signal decoding. More particularly, the network includes a circuit for current sensing the desired parameter and providing an analog sensor output signal related to the unit measure (i.e., relative value...

A multipoint communications system for transmitting the values of a multiplicity of analog parameters from one point digitally to another point and reconverting then into analog parameters. The system includes a plurality of input modules which communicate with respective output modules over a communications link. The input and output modules are configured similarly with a control processor connected to either multiplexing circuitry, in the case of an input module, or demultiplexing circuitry i...

The circuit includes a loop (3) in which a signal current flows; a supply voltage generation circuit (1); a signal conversion circuit (2); a switch (5) operative to connect either the supply voltage generation circuit or the signal conversion circuit into the loop (3) at any instant, the outputs of the supply voltage generation circuit and the signal conversion circuit being supplied to a common load (4) which controls operation of the switch (5); and a pair of capacitors (6,7) connected across ...

A universal pressure measurement interface ("UPMI") according to the invention enables interfacing of a multiplicity of pressure transmitters to a data acquisition system. The UPMI provides the necessary DC power and signal flow for field test measurements and is suitable for direct application in various sites with line voltage of from 100 to 240 VAC at 50-60 Hz.

A three wire transmitter bidirectionally communicates AC signals to and from a first external device and sends DC signals to a second external device. The transmitter includes a communication circuit which is energized from power and common terminals and includes memory storage for transmitter status and a process variable (PV). The communication circuit receives a sensor output indicative of the PV and provides the DC signal and the AC signal to a signal terminal which connects to both external...

A self-testing and mutual testing method of multifunctional remote control transmitters includes the steps of self-testing multifunctional remote control transmitters by selecting a self-testing mode using a test pin switch, mutually testing multifunctional remote control transmitters by selecting a mutual testing mode, compressing and analyzing data by the multifunctional remote control transmitters, and displaying the error condition. The method facilitates checking faults occurring in multifu...

A method for detecting and correcting noise occurring by internal or external factors in a PPM signal waveform analyzing device such as a multifunctional remote control transmitter includes the steps of determining the existence of a carrier in a received PPM signal, detecting and correcting for a noise signal included in each signal when the carrier is present, requesting retransmission of the signal for unrestorable noise signals, and detecting and correcting for noise caused when the weakenin...