Tech Briefs

Software to Control and Monitor Gas Streams

This software package interfaces with various gas stream devices such as pressure transducers, flow meters, flow controllers, valves, and analyzers such as a mass spectrometer. The software provides excellent user interfacing with various windows that provide time-domain graphs, valve state buttons, priority-colored messages, and warning icons. The user can configure the software to save as much or as little data as needed to a comma-delimited file. The software also includes an intuitive scripting language for automated processing. The configuration allows for the assignment of measured values or calibration so that raw signals can be viewed as usable pressures, flows, or concentrations in real time. The software is based on those used in two safety systems for shuttle processing and one volcanic gas analysis system.

Mass analyzers typically have very unique applications and vary from job to job. As such, software available on the market is usually inadequate or targeted on a specific application (such as EPA methods). The goal was to develop powerful software that could be used with prototype systems. The key problem was to generalize the software to be easily and quickly reconfigurable.

At Kennedy Space Center (KSC), the prior art consists of two primary methods. The first method was to utilize LabVIEW and a commercial data acquisition system. This method required rewriting code for each different application and only provided raw data. To obtain data in engineering units, manual calculations were required. The second method was to utilize one of the embedded computer systems developed for another system. This second method had the benefit of providing data in engineering units, but was limited in the number of control parameters.

Other products allow the same end effect, except multiple computers would be required along with multiple software packages. This is compounded by the difficulty in timing the various software products. The software package described here is a combination of gas stream monitoring software products. It combines pressure monitoring and control, fluid flow monitoring and control, and many chemical analysis products, including, but not limited to, mass analyzers, turbo pumps, dew point sensors, oxygen sensors, temperature sensors, and the like. It allows for real-time display of raw data as well as reassigned calibration data. The software is capable of timing events as well as running scripts for semi-autonomous operation. The software also records this variety of data with proper timing.

This complex software package is composed of two primary parts: hardware communications and user interfacing. The hardware interfacing section allows for the computer to transfer data and commands (via digital or analog signals) to a wide variety of system components such as sensors, valves, transducers, analyzers, pumps, etc. The hardware interfacing section also allows for the recording of the transferred data/commands to be stored on the local computer. The user interface section gathers the data from the hardware interfacing section and presents it to the user in various user-configurable methods. The two most common methods of providing data to the user are via time-domain charting and real-time parameter value/status.

This work was done by C. Arkin, Charles Curley, Eric Gore, David Floyd, and Damion Lucas of Kennedy Space Center. KSC-13643

This Brief includes a Technical Support Package (TSP).

Software to Control and Monitor Gas Streams (reference KSC-13643) is currently available for download from the TSP library.

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