Showing papers on "Sensor node published in 1995"

Data transmission system and method

Abstract: The data transmission method employs IEEE P1394 protocol. The data header of the transmitted isochronous packet is added with a node identifier identifying the transmitter node, so that the receiver node can immediately identify the transmitter node, and can thereby request the transmitter node to maintain transmission. A Broadcast channel is a default channel used for isochronous packet transmission, unless a different channel number is otherwise specified. Thus, it is not necessary for the user to coordinate the channel number used by the transmitting and receiver nodes. It is also not necessary for the transmitter node to notify the receiver node, or the receiver node to notify the transmitter node, of the channel number used.

Sensor connection system

Abstract: A sensor connection apparatus for connecting a plurality of sensors to a process controller having a bus for transferring information, wherein each sensor produces an output corresponding to a sensed condition, includes a respective sensor cable that can be connected at one end to each sensor; a concentrator having each of the sensor cables connected thereto; the concentrator being connected to the bus; the concentrator comprising a circuit for producing for each sensor and associated sensor cable connected thereto a first signal in response to the sensor output and a second signal that corresponds to a sensor cable condition; the circuit further operating to couple the first and second signals for each sensor connected to the concentrator onto the bus for access by the process controller. In one embodiment, the concentrator transmits data to the process controller using a standardized communications protocol, such as CAN, using a microcontroller and transceiver.

Maximum demand power control apparatus

Abstract: A maximum demand power control apparatus is provided which can be easily wired up even when a large number of loads are to be controlled, and wherein the burden related to control does not fall on one device. In the construction, a sensor node 2 estimates the consumption power amount for a whole facility on the basis of the pulses outputted from an integrating wattmeter 1, and outputs power warnings information to a transmission line 5 based on the estimation. Control nodes 3a to 3c respectively control the consumption power of power loads 4a to 4c corresponding to the respective control nodes, according to power warning information received via the transmission line 5.

A Sensor Signal Processor

Abstract: This paper describes a universal sensor interface named the sensor signal processor (SSP). The SSP consists of digital and analog blocks. The digital block generates a waveform which simulates the sensor characteristic in the time domain. An analog block processes a sensor output in the form consistent with the output of the digital block. Comparing both the outputs the SSP provides a linear digital equivalent of the measurand. For generating the waveform, the direct digital synthesis (DDS) and oversampling delta-sigma demodulation techniques are used. Eliminating precision devices, these techniques allow the high yield, monolithic implementation. The scale adjustment and cancellation of the offset and cross-sensitivity are also possible by adjusting the reference voltage involved in the DDS. Thus, the SSP satisfies almost all requirements for a universal interface. An application to a capacitive pressure sensor is also given to demonstrate its validity.<>

Analog-digital conversion system with automatic offset tracking and correcting circuit and method of operation

Abstract: An analog-to-digital conversion system (6) is provided which includes an analog-to-digital converter (8) having a first node (NODE 1) and a second node (NODE 2). An automatic offset tracking and correcting circuit (10) is coupled to the first node (NODE 1) and the second node (NODE 2).