Abstract: A driver boost signaling circuit provides a pulse boost to the first cycle of an output pulse wave applied to an associated load. The circuit includes a signal generator circuit generating a signal including a series of pulses, a determining circuit determining a high impedance state of a signal load line and a first one or more cycles of the series of pulses applied to the load line following the high impedance condition, and a receiving circuit receiving a control signal. A logic circuit generates first and second logical signals responsive to the control signal and to the determining circuit determining the first one or more cycles and other cycles of the series of pulses.

Abstract: A driver boost signaling circuit provides a pulse boost to the first cycle of an output pulse wave applied to an associated load. The circuit includes a signal generator circuit generating a signal including a series of pulses, a determining circuit determining a high impedance state of a signal load line and a first one or more cycles of the series of pulses applied to the load line following the high impedance condition, and a receiving circuit receiving a control signal. A logic circuit generates first and second logical signals responsive to the control signal and to the determining circuit determining the first one or more cycles and other cycles of the series of pulses.

Abstract: A method and system for resolving contentions among passive identification tags. A reader may divide a possible range of tag values into a number of smaller ranges. For each smaller range, the reader may then poll the tags to determine which tags have tag values that fall within the smaller range. If more than one tag responds simultaneously, then the reader may further divide the smaller range into even smaller ranges and poll the tags with respect to those even smaller ranges. Once the range partition gets small enough, the reader may then opt to poll the tags for a match of each possible value in the range, rather than partitioning further. This arrangement enables the reader to efficiently identify tags, by quickly eliminating from analysis any range of tag values to which no tags match or only one tag matches.

Abstract: A method and system for resolving contentions among passive identification tags. A reader may divide a possible range of tag values into a number of smaller ranges. For each smaller range, the reader may then poll the tags to determine which tags have tag values that fall within the smaller range. If more than one tag responds simultaneously, then the reader may further divide the smaller range into even smaller ranges and poll the tags with respect to those even smaller ranges. Once the range partition gets small enough, the reader may then opt to poll the tags for a match of each possible value in the range, rather than partitioning further. This arrangement enables the reader to efficiently identify tags, by quickly eliminating from analysis any range of tag values to which no tags match or only one tag matches.

Abstract: A cable drive circuit allows a transmitter in a process control system to drive signals across a capacitive length of cable. The cable drive circuit uses a charge pump to store charge, which is then used in conjunction with open drain outputs to transmit logic signals across a cable to a peripheral at the other end of the cable. A microcontroller or other device specifies the number of communication pulses to send across the cable before allowing the charge pump to recharge. By transmitting communication pulses for a small percentage of the time the average current is minimized, making the circuit suitable for operation under the 4-2OmA standard for two-wire devices.

Abstract: A measurement system utilizes a sensor formed in a semiconductor on insulator structure that has an offset related to the time that power is applied. A controller applies power, obtains readings and removes power so as to minimize any effect of the offset.

Abstract: A field mounted transmitter for use in a two-wire process control loop includes a sensor, measurement circuitry and a power supply. The sensor senses a process variable of a process which is transmitted over the control loop by the measurement circuitry. The power supply is powered by a current flowing through the control loop and powers the measurement circuitry. The power supply includes an inductive element coupled to the measurement circuitry and a switch which selectively couples the inductive element to the control loop.

Abstract: In this invention, a multivariable transmitter providing an output representative of mass flow has a dual microprocessor structure. The first microprocessor compensates digitized process variables and the second microprocessor computes the mass flow as well as arbitrating communications between the transmitter and a master. In a second embodiment of the present invention, a first microprocessor compensates digitized process variables, a second microprocessor computes an installation specific physical parameter such as mass flow and a third microprocessor arbitrates real-time communications between the transmitter and a master.

Abstract: An improved error detection for microprocessor-based transmitters in two-wire process control loops operating in the process control industry. In particular, techniques are shown which are useful in solving malfunctions or failures of microprocessor-based transmitters. When the transmitter is energized, the impedance of the process loop cabling is resolved and stored, displayed or transmitted as desired. The loop impedance is used to calculate potential of a power supply used to power the control loop. This information is used in testing the two-wire loop.