Showing papers on "Sensor node published in 1997"

Multifunction sensor and network sensor system

Abstract: A multifunction sensor provides a plurality of parameter sensors in one sensor module which can interface with and control operation of one or more processor control systems in an occupied space networked environment such as a commercial building. The multifunction sensor comprises at least an occupancy sensor, an ambient light sensor, and a temperature sensor. A common network communications and control processor is coupled to a common communication transceiver, and are shared in common by the occupancy sensor, the ambient light sensor and the temperature sensor, such that the multifunction sensor can interface with and control operation of one or more processor control systems. A plurality of the multifunction sensors are placed at different locations throughout the building. The multifunction network sensor system further comprises energy management and security controller systems, and a common data communication network which connects to the multifunction sensors and the controller systems to form a local operating network in the building. Each multifunction sensor is assigned a unique location address, and can transmit and receive data, including its own unique address, over the data communication network.

Networked sensor system

Abstract: A networked sensor system that simultaneously acquires, processes, and transmits sensor data under the control of a central processing unit. The system includes sensors connected to sensor processing modules. The sensor processing modules are serially coupled together and to the central processing unit by a fiber optic network. The central processing unit can change the sensor sampling rate by changing a global clock rate, can describe the number and layout of sensor processing modules and their associated sensors allowing for reconfiguration in accordance with a desired application, and can download code to the sensor processing modules for modifying processing functions for a given application. The global clock also allows for synchronous sampling throughout the network. Sensor gain in the sensor processing modules is dynamically programmed by the central processing unit.

Integrated smart sensor calibration

Abstract: In many applications electronic sensors are used to improve performance and reliability of measurement systems. Such sensors should provide a correct transfer from the physical signal to be measured to the electrical output signal. One important step to achieve this, is to calibrate each sensor by applying different reference input signals and adjusting the sensor transfer accordingly. Besides expensive reference equipment the calibration process takes much time and attention per individual sensor, which means a considerable increase in sensor production costs. By including at the sensor or sensor interface chip a programmable calibration facility the calibration of such smart sensors can easily be automated and can be executed for a batch of sensors at a time, thus minimizing the calibration time and costs. This paper presents a calibration method and options for integration in the smart sensor concept, in hardware as well as in software. An advantage of the proposed method is that it does not need a large matrix of calibration data, which needs to be stored in a look-up table or converted into a correction formula, but instead it uses a step-by-step approach to correct the sensor transfer at each calibration measurement until the error is sufficiently small.

Routing signals through a wireless communication system comprising a network of linked nodes

Abstract: A wireless communication system comprises a network of nodes 2 connected by point-to-point links 3 using highly directional antennae. Each node determines if a received signal includes information for another node and if so, a signal including the information is transmitted to another node. Information is routed or hopped from node to node until it reaches its destination node. The nodes may be subscriber stations or repeaters. Various network topologies are described including fully interconnected, linear chain, tree, lattice, hypercube and combinations. Multiple paths for signal transmission can be chosen each consisting of an even number of links to maintain synchronisation of transmission and reception between nodes. A copy of the information may be sent on a different path or the information may be split between two paths. Traffic is routed by addresses added at each node or by a central system controller, and may be determined by congestion or node availability. Each link from a node may be associated with one or more time slots for transmission or reception. At least one link of a node may use a different frequency to prevent interference.

Transmission control method in a network system for interactively transmitting a signal between node devices and network system using the same

Abstract: The present invention discloses a network system for an interactive transmission in first and second directions. The network system includes a plurality of node devices, and a first node device of the node devices can selectively output a signal in the first direction or perform the returning output of a signal. A second node device adjacent to the first node device outputs a signal to the first node device through a channel which is used by the first node device for the returning output, hence the first and second node device are controlled such that those first and second node devices do not use the returning channel of the first node device concurrently.

Optical network control system and optical network

Abstract: PROBLEM TO BE SOLVED: To provide the optical network control system and the optical network in which a high effective throughput is realized. SOLUTION: The optical network is provided with a dummy node N5 provided with an idle signal generating circuit 50, an optical transmitter 14-5, an optical receiver 15-5, and a buffer memory 11-5. An optical switch 21 is capable of multi-casting. In the case that no packet is transferred, the dummy node N5 multi-casts an idle signal to an optical receiver 15-5 of each node. In the case that nodes N1, N2 are going to send a packet to a node N3, an arbitration circuit 22 makes arbitration. As soon as a packet is transferred from the transfer node N1 survived as the result of arbitration to the transfer destination node N3, the defeated transfer source transfers a packet to the dummy node N5 at first. Then the dummy node N5 transfers the packet to the transfer destination node N3. COPYRIGHT: (C)1998,JPO

Node interconnection using multiple channels

Abstract: The present invention discloses a network system for an interactive transmission in first and second directions. The network system includes a plurality of node devices, and a first node device of the node devices can selectively output a signal in the first direction or perform the returning output of a signal. A second node device adjacent to the first node device outputs a signal to the first node device through a channel which is used by the first node device for the returning output, hence the first and second node device are controlled such that those first and second node devices do not use the returning channel of the first node device concurrently.