October 2009
Product Release News – Rotadata Telemetry Data Software (RTDS)
Background
Rotadata have over 30 years’ experience in the design, development, manufacture and application of gas turbine instrumentation. Throughout its history, the company has always invested in well-focused Research and Development Programs in order to fully exploit emerging technologies in innovative ways. This allows Rotadata to constantly extend the capabilities of the Electronic, Mechanical and Software building blocks that form the basis of its highly successful range of products.
Rotadata has now completed the last package of work in a long-term effort to provide a “Complete Engine Turbine Rotor Measurement System”. For many years, Rotadata has had the ability to design and install instrumentation onto Clients’ rotating machinery and monitor these instruments using its own Telemetry Units. More specifically, these capabilities include :
i) The application of low temperature and high temperature strain gauges to engine rotating parts (e.g. shafts, blades, discs and impellers).
ii) Engine rotor assembly and the routing /clipping of sensor lead wires.
iii) Design and manufacture of state of the art digital telemetry units, which are used to transfer rotating signals to a ground station situated in either the test cell or control room.
iv) Pre-delivery system test, on-site installation and instrumentation system commissioning.
In addition, Rotadata have now completed the development of a suite of computer programs, collectively known as “Rotadata Telemetry Data Software” (RTDS), which are used to acquire, store and process the data stream that is generated by the telemetry unit. This means that Rotadata is probably now unique amongst the world’s instrumentation providers, since it can deliver a complete end-to-end instrumentation service for rotating parts (i.e. the total design of the instrumentation system, application of hardware onto engine parts and the collection/processing of data).
From October 2009, Rotadata will be offering an RTDS package to all customers who purchase new telemetry systems.
Overview of Rotadata Telemetry Data Software (RTDS)
RTDS is a suite of programs that has been developed using Microsoft® Visual C#®, National Instruments™ Graphics Routines and LabVIEW® Frequency and Order Analysis Functions. It is designed to run on a high specification Personal Computer (PC), and has only recently become possible because of the increases in both processor speeds and the storage capacity of hard disk drives. At present, RTDS is designed to capture, store and process telemetry data acquired from instruments that are sampled at high frequency. This is usually limited to strain gauges, whose output is typically sampled at greater than, 120,000 samples/second. All other telemetry data obtained from instruments that are sampled at slow speeds (e.g. thermocouples, steady state strain gauges and pressure transducers) continues to be acquired, displayed and stored using Rotadata’s existing software package, DADSXP.
The RTDS suite of programs allows the user to carry out 3 main tasks:
i) Pre-Test Configuration
This software module is run before engine testing starts, and is used to create a database that defines the configuration of the whole instrumentation package. The user-friendly interface is used to enter details relating to sensor type, sensor calibration and parameter identification. It is also used to assign data logging channels to the corresponding sensors, as well as select which channels are to be monitored.
ii) Collection and Real-Time Display of Test Data
This software is used whilst the engine test is in progress, in order to collect and store (on hard drive) the following information:
- Digitised data extracted from the bit stream from the Telemetry Unit.
- Telemetry health monitoring data (temperatures and vibration levels).
- Digitised data from test bed analogue inputs, which can be connected to a variety of instruments that produce an analogue signal (e.g. pressure transducers, speed probes, tip clearance measurement system).
- Time code information (for time-stamping data).
A master display window shows instantaneous readings from all channels, whilst two additional windows can be used to show detailed graphs for any particular channels that might be of interest. The first additional window can simultaneously show graphs of data from any 6 parameters, plotted against time. The second additional window is used to show the results of various frequency analysis techniques (e.g. power spectral density) for up to 4 selected strain gauge channels.
iii) Post-Test Processing
This software allows data for any of the recorded channels to be read from disk and then analyzed in a manner that is appropriate for the particular data type. For example, it is easy to produce a time history for any of the test bed analogue channels (connected to miscellaneous instrumentation). However, the greatest number of options and the heaviest computational effort relate to the processing of strain gauge data. Since calculations are carried out “off-line”, more time is available, so it is possible to produce a variety of 2D and 3D plots showing a wide range of amplitude-time relationships, frequency spectra and order tracking.
Example of the Frequency Analysis Waterfall
Advantages of using RTDS
Rotadata Telemetry Data Software (RTDS) offers the following advantages:
- It enables the client to purchase a full turn-key system for rotating instrumentation. This means that Rotadata are able to design, manufacture, assemble and test the complete end-to-end measurement system (including all instrumentation, telemetry unit and data acquisition/processing software).
- Since RTDS uses standard PC components as its operating platform, it is relatively inexpensive when compared with traditional mainframe based, facility data acquisition systems.
- In its present form, RTDS can be configured to handle a wide range of instrumentation options.
- Because of its modular design, Rotadata can easily tailor RTDS to suit almost any combination of instrumentation that is likely to be required.
- Rotadata could easily tailor RTDS to be compatible with the acquisition and processing of additional non-rotating instrumentation.
- RTDS is forwards and backwards compatible with any telemetry system. It can be sold either separately to supplement the features of a current installation or to compliment any new telemetry system.
Who would find RTDS useful ?
Although Rotadata Telemetry Data Software (RTDS) will be available for use with all new Rotadata Telemetry Systems, it could also be configured for use with existing systems. It would be particularly useful for the following groups of people:
- Clients who require rotating instrumentation and who are also setting up a new test facility and associated data acquisition equipment.
- Clients who have a test bed with data acquisition equipment, but insufficient channels to accept signals from all stationary and rotating instrumentation.
- Any client who requires a low cost alternative to a facility based data acquisition system.
ORDER SPECTRAL MAP (Waterfall)
