Abstract:
A diagnostic system and method for a field device in a process control apparatus is provided. At least one sensor is associated with the process control apparatus, and a computer is adapted to receive data from the sensor and to detect an occurrence of a predetermined process event. A memory device is operatively connected to the computer and adapted to store sensor data received by the computer at a time corresponding to the occurrence of the predetermined process event.
Abstract:
Separate, but related, firmware programs for multiple microprocessor-controlled irrigation controllers (1) that are interrelated in their control of irrigation within an irrigation system are generated off-line at a personal computer (32). The programs are downloaded into a transportable memory device (30) that holds sixty-four separate programs. The memory device (30) is transported to each irrigation controller (1) and plugged to a digital communication channel (15). The device automatically identifies itself to the controller (1), and vice versa. The appropriate program is automatically uploaded from the device (30) to the controller (1). The controller's (1) old program and its historical irrigation record data is loaded into the device (30) and delivered to the personal computer (30) for validation and analysis. A wireless remote test command assembly (61), an extension maintenance panel (42), or a radio-link central module (50) may be alternatively connected to the controller's digital communication channel (15).
Abstract:
A two-wire process variable transmitter (12) for use in an industrial process (10) includes a process variable sensor (14) configured to sense a process variable of a process fluid of the industrial process (10). Output circuitry (36) provides an output on a two-wire process control loop (18) which is related to the sensed process variable. Terminal voltage measurement circuitry measures (92) a voltage at terminals (40) of the process variable transmitter (12). The terminal voltage is a voltage measured across an electrical connection (40) of the two-wire process variable transmitter (12) to the two-wire process control loop (18). A microprocessor (30) performs loop diagnostics on the two-wire process control loop (18) based upon a loop current and the measured terminal voltage. The microprocessor (30) determines coefficients of a polynomial equation which relates loop current and terminal voltage during normal operation of the two-wire process variable transmitter (12) and performs subsequent diagnostics based upon the coefficients of the polynomial.
Abstract:
A two-wire process variable transmitter (12) for use in an industrial process, including a process variable sensor (14) configured to sense a process variable of a fluid of the industrial process. Output circuitry (36) is configured to provide an output on a two-wire process control loop (18) which is related to the sensed process variable. Loop current measurement circuitry (36) measures a loop current flowing through the two-wire process control loop (18) and terminal voltage measurement circuitry (36) measures a voltage related to a terminal voltage of the process variable transmitter (12). The terminal voltage can be a voltage measured across an electrical connection of the two-wire process variable transmitter (12) to the two-wire process control loop (18). Input circuitry (36) is configured to receive a diagnostic command from the two-wire process control loop (18). A microprocessor (30) configured to perform loop diagnostics on the two-wire process control loop (18) based upon the measured loop current and terminal voltage in response to receipt of a diagnostic command from the two-wire process control loop (18).
Abstract:
A processor controls the operation of at least one sewing machine with its additional accessories and regulates the rotation speed of the positioning control of the sewing machine. The characteristics for controlling the operation and the regulation of the rotation speed may be predetermined and modified by digital programming signals of a programmer.