A signal converter which receives signals from a plurality of sensor terminal ends to detect physical quantities in a plant and conducts a necessary correction for the signals to send the signals to a host computer or which transmits signals from the host computer to operation terminal ends in the plant includes a sensor terminal end amplifier including a processing unit for receiving a signal from a sensor terminal end and conducting a predetermined amplifying operation for the signal and a storage unit in which information items related to the sensor terminal and the processing unit are stored, an operation terminal end amplifier including a converting unit for converting signals into predetermined control signals which can be received by the operation terminal end and a storage unit in which information items related to the operation terminal end and the converting unit are stored, and a signal converting section including a connecting unit for connecting the sensor terminal amplifier section to the operation terminal amplifier section and a signal processing unit for conducting signal processing to communicate with the host computer.

A fuel injection system for automotive diesel engine is provided which is equipped with a fuel pressure sensor working to measure the pressure of fuel in an accumulator and a pressure-reducing valve working to drain the fuel from the accumulator. The system is designed to ensure enhanced reliability of diagnosis of the pressure-reducing valve. The system works to make a temporal diagnosis of the pressure-reducing valve based on the behavior of the pressure in the accumulator upon opening of the pressure-reducing valve after an ignition switch is turned off. After elapse of a given period of time, when it is determined that a value of the pressure in the accumulator, as measured by the fuel pressure sensor, lies near the atmospheric pressure, the system determines that the fuel pressure sensor is operating properly and fixes the temporal diagnosis of the pressure-reducing valve ultimately.

The method and the data processing system of the invention monitor the operating states of a technical plant. The operating states of the technical plant are characterized with measured values measured or modeled at a lowest level of the system. The plant is monitored with the measured values and with technological knowledge relevant to the operation of the technical plant stored in a memory of the data processing system. First, the measured values are processed and converted into plant symptoms specific of the associated operating states. Next, a diagnosis of the operational state of the plant is established from the plant symptoms and a significance value is assigned to the diagnosis, or a significance value is first assigned to the plant symptom and the diagnosis is prepared therefrom. The assignment of the significance is based on the technological knowledge. The diagnostic information is thus rated before it is appropriately forwarded to the user surface.

The pneumatic power system of this invention is a process that measures at very high resolution the pressure and/or rate of flow profile at various points throughout the pneumatic circuitry of a piece of pneumatic equipment in a manufacturing environment. Candidates for this process must use compressed air to move, lift, convey, actuate or otherwise influence the manufacturing process. The signature profile allows for high resolution measurement and recording of pressure and/or rate of flow changes throughout the process when the equipment is fully adjusted and tuned to produce product at maximum efficiency and quality. Once optimum adjustments are obtained, the pneumatic profiling process records the pressure profiles throughout the system and uses the model profile as a benchmark to compare all subsequent profile data.

Systems integrate in a straightforward and user-friendly manner the testing and certification of different functional and performance characteristics of intravenous pumps on site by non-technical people.