Abstract:
A field device (14) for use in an industrial process control or monitoring system (10) connects to a two-wire process control loop (16). The loop (16) carries data and provides power to the field device (14). RF circuitry (22) in the field device (14) is provided for radio frequency communication. A power supply (18) powers the RF circuitry (22) using power received from the two-wire process control loop (16).
Abstract:
A pressure transmitter (20, 21, 60, 150, 190, 200, 201) with a transmitter housing (22, 62, 152) having an outer wall (64, 154) providing thermal resistance (66). The outer wall (64, 154) extends from an isothermal island (68, 156) at a first end (70) to a heat sink island (72, 159) at a second end (74). The isothermal island (68, 156) includes a fluid inlet (38, 76, 158, 202), and pressure and temperature sensors (34, 78, 164; 42, 80, 166). The heat sink island (72, 159) includes a primary heat load device (40, 41, 110, 174) that is heat sunk to an outer shell (104, 170) of an electrical connector. The connector (102, 168) contacts (24, 26, 108, 172) carry a current controlled by the transmitter, and a portion of the current is conducted by a primary heat load device (40, 41, 110, 174). A circuit board (120, 176) controls the current to represent the pressure. A high accuracy, temperature compensated current output represents pressure.
Abstract:
Une unité de commande (22) intelligente installée sur site, destinée à réguler un processus, reçoit des signaux et envoie une sortie d'instructions par un circuit (18) à deux fils alimentant l'unité de commande (22). Une partie d'entrée (50) reçoit les signaux, lesquels peuvent être des instructions représentatives d'instructions ou d'ensembles d'instructions, des variables de processus détectées par des unités de commande extérieures ou des valeurs de consigne représentatives d'un état de processus voulu. Les instructions sont représentatives d'une condition de commande du processus, et règlent une partie de commandes (52) se trouvant dans l'unité de commande (22), afin de produire la sortie d'instructions (58) conformément à la condition de commande. La sortie d'instructions (58) peut être une fonction de la différence entre la valeur de consigne du processus et une variable de processus, ou une fonction d'une combinaison linéaire d'une variable de processus ainsi que son intégral de temps calculé et des fonctions dérivées du temps. Une partie de détection (100) se trouvant dans ladite unité de commande (22) peut détecter et établir l'échelle d'une variable de processus afin de produire également la sortie d'instructions (58). Ladite unité de commande (22) peut comprendre une partie régulatrice, commandée par la sortie d'instructions (58), laquelle régule l'application d'une force mécanique, hydrolique, pneumatique ou électromagnétique appliquée au processus.
Abstract:
A process variable transmitter (100) for use with a removable operator interface (202) has a non-volatile memory (204) and a latching component (210). The non-volatile memory (204) stores device settings (206). The latching component (210) prohibits changes to transmitter settings if the removable operator interface (202) is absent. Circuitry in the transmitter (100) detects the presence of the removable operator interface (202). The removable operator interface (202) can include zero and span settings.
Abstract:
An adapter (300) for coupling to a process control transmitter (308) of the type used to monitor a process variable in an industrial process includes a first connection configured to couple to a first side of a two wire process control loop (302), a second connection configured to couple to a second side of the two wire process control loop (302) and in series with a first connection to a process control transmitter (308), and a third connection configured to couple to a second connection of the process control transmitter (308). Wireless communication circuitry is coupled to at least the third connection and is configured to provide wireless communication for the process control transmitter (308). Intrinsic safety circuitry (460) coupled to at least one of the first, second and third connections is configured to limit transfer of electrical energy to a value which is less than an intrinsic safety value.
Abstract:
A process variable transmitter (100) for use with a removable operator interface (202) has a non-volatile memory (204) and a latching component (210). The non-volatile memory (204) stores device settings (206). The latching component (210) prohibits changes to transmitter settings if the removable operator interface (202) is absent. Circuitry in the transmitter (100) detects the presence of the removable operator interface (202). The removable operator interface (202) can include zero and span settings.
Abstract:
A field hardened industrial device (200) is described with a housing (208) of the device having electrically conductive walls surrounding a cavity (206) with an open end. An electronics assembly (292) is adapted to fit within the cavity. The device includes a circuit card assembly (270), which is a multi-layered printed wiring board with pass-through electrical connections and an embedded ground plane (350) electrically coupled to the housing (202) to shield the electronics assembly (292) from electromagnetic interference and to provide environmental protection to the electronics assembly.
Abstract:
A pressure transmitter (20, 21, 60, 150, 190, 200, 201) with a transmitter housing (22, 62, 152) having an outer wall (64, 154) providing thermal resistance (66). The outer wall (64, 154) extends from an isothermal island (68, 156) at a first end (70) to a heat sink island (72, 159) at a second end (74). The isothermal island (68, 156) includes a fluid inlet (38, 76, 158, 202), and pressure and temperature sensors (34, 78, 164; 42, 80, 166). The heat sink island (72, 159) includes a primary heat load device (40, 41, 110, 174) that is heat sunk to an outer shell (104, 170) of an electrical connector. The connector (102, 168) contacts (24, 26, 108, 172) carry a current controlled by the transmitter, and a portion of the current is conducted by a primary heat load device (40, 41, 110, 174). A circuit board (120, 176) controls the current to represent the pressure. A high accuracy, temperature compensated current output represents pressure.
Abstract:
In this invention, a multivariable transmitter (2) providing an output representative of mass flow has a dual microprocessor structure. The first microprocessor (72) compensates digitized process variables and the second microprocessor (80) computes the mass flow as well as arbitrating communications between the transmitter (2) and a master (88).