Abstract:
A wireless field device for use in controlling or monitoring an industrial process, includes a process interface configured to couple to a process fluid. Field device circuitry is coupled to the process interface and configured to measure or control a process variable. Wireless communication circuitry is configured to provide wireless communication. At least one electrical access terminal is configured to provide an electrical connection to circuitry of the field device. A power supply is configured to power the wireless field device. The power supply includes a removable primary power source to provide power to the field device for extended periods of time. A secondary power source is configured to provide power to the field device when the primary power source is removed.
Abstract:
A field device includes a power control module, a network interface module that communicates over a wireless network, and a device interface module for operating transducers, such as a sensor or an actuator. The power control module controls distribution of electrical power so that the network interface module receives electrical power while it is attempting to join the wireless network. Once the network interface module has joined the wireless network, the power control module allows the network interface module and the device interface module to share electrical power.
Abstract:
A pressure transmitter assembly (106) for measuring a pressure of a process fluid (104) includes an isolation diaphragm assembly (120). A pressure sensor (130) is spaced apart from the isolation diaphragm assembly (120) to provide thermal isolation. A conduit (122) extends from the isolation diaphragm assembly (120) to the pressure sensor (130) and is configured to carry isolation fill fluid.
Abstract:
Un transmetteur (10) de type rétroréactif à charge équilibrée génère des paquets de charge représentatifs d'un paramètre détecté. On améliore sa performance en connectant une résistance (R1), (R2) entre une réactance (C1), (C2), (CL1), (CL2) génératrice de paquets de charge et un intégrateur (30) afin de réduire les parasites provoqués par des phénomènes transitoires de commutation et par le bruit de fond couplé aux circuits générateurs (12) des paquets de charge par capacité parasite. Les paquets de charge sont intégrés par l'intégrateur (30) et la sortie de l'intégrateur est appliquée sur une base sélective à l'entrée d'un comparateur (32). La sortie du comparateur (32) sert à commander l'équilibrage. L'entrée du comparateur (32) est sélectivement connectée à la sortie de l'intégrateur (30), à une première tension d'alimentation ou à une deuxième tension d'alimentation afin d'assurer une sortie stable du comparateur (32) aux moments critiques où la charge est fournie à l'intégrateur (30).
Abstract:
A wireless mesh network is formed by nodes (GW1, GW2, A-F, X-Z) having a regular active schedule for transmitting and receiving messages, and a fast active schedule mode that is locally activated when a demand exists for transmission of a larger number of messages. As each node transmits a message to another node, the transmitting node includes a message buffer queue parameter that indicates the number of messages in the transmitting nodes, pending message queue. The receiving node determines, based upon the message buffer queue parameter received and its own capacity, whether to continue on the regular schedule, or to activate the fast active schedule. If the fast active schedule is activated, the receiving node sends a special acknowledge message back to the sending node, so that both nodes will transmit and receive messages over a fast active schedule link until the message buffer of the sending node has been reduced and the fast active schedule can be deactivated in favor of the regular active schedule.
Abstract:
An adapter (300) for coupling to a process control transmitter of the type used to monitor a process variable in an industrial process is provided. The adapter includes I/O circuitry (342) configured to couple to a two wire process control loop (302) and to the process control transmitter and communicate on the process control loop (302). Wireless communication circuitry (344) couples to the two wire process control loop (302) and is configured to transmit an RF signal. Power supply circuitry (350) provides power to the wireless communication circuitry.