Abstract: A low latency peripheral device sharing system has a host computer with an operating system, a kernel memory buffer, applications, device specific drivers, and a peripheral server driver. The server driver intercepts function calls invoking the local serial ports, and passes standard serial data from the application to a local area network. A device server on the local area network reads the data using a hybrid read block (semi-blocking read), and writes the data to the FIFO registers of the serial device and the remaining data to a queue for the serial device. Finally, the device server times the serial data and returns an intercharacter interval timer flag to the host computer to terminate a read operation.

Abstract: A process transmitter communications circuit has link terminals which are coupled to a process link, which supplies power to the circuit. A power source is coupled to one of the link terminals and is independent from the power supplied from the process link. Communications circuitry is coupled to the power source and link terminals, which transmits a transmitter signal over the process link, through the link terminals. A power sensing component is coupled to at least one of the link terminals and the communications circuitry and senses whether the power supplied by the process link is inadequate to transmit the transmitter signal. A power control component is coupled to the power source, the link terminals and the communications circuitry and selectively applies power from the power source to the communications circuitry for transmitting the transmitter signal when the power sensing component senses there is inadequate power supplied by the process link.

Abstract: A level sensor for use in a process application measures height of a product in a tank. The level meter includes a microwave feedhorn directed into the tank, an electronics housing spaced apart from the feedhorn and a microwave waveguide extending therebetween. A microwave transducer in the housing couples to the waveguide and sends and receives microwave signals. A microprocessor in the housing identifies echoes from the microwave signals which are generated and sensed by the microwave transducer. The microprocessor determines height of the product based upon a microwave echo from the product and a microwave echo from the feedhorn. The microprocessor compensates for the effect of propagation delay through the waveguide on height measurements with the feedhorn echo and provides an output related to height of the product in the tank.

Abstract: A barrier device threadably mounts to a cabling aperture on a field mounted transmitter. The field mounted transmitter receives and transmits signals, and is wholly powered by a current loop circuit. The barrier device has a conductive housing with at least a first and a second aperture and a pair of conductors passing through the first aperture of the barrier device, for connecting to a terminal block in the transmitter. A pair of signal terminals, preferably as ring tongue lug, is mounted in the second aperture of the barrier device. The signal terminals are connectable to a handheld communicator, which is used to calibrate, monitor and test the transmitter. A barrier circuit is mounted in the housing and is electrically connected between the signal terminals and the conductors. Signals from the communicator access the terminal block through the barrier circuit, and the barrier circuit limits the power available at the signal terminals.