Mats Rieschel (European Space Agency)
The Maser-8 sounding rocket mission funded by the European Space Agency (ESA) and launched in May -99, contained four experiments. For one of these experiments, the Automation and Robotics Section of ESA was asked to develop the ground data distribution network to deliver telemetry data to monitor stations both locally at the launch site and also remotely to the Institute of the Principal Investigator (PI) in Brussels, Belgium. The PI team wanted to develop their own scientific MMI applications running under Windows. The data rate from the rocket is too high to transfer all data across an ISDN network, so it was necessary to introduce a filtering system between the telemetry distribution and the scientific MMI. This was solved by introducing a QNX computer running the Cascade DataHub. A small application extracted the data needed by the MMI and put them into the Cascade DataHub. From there on it was automatically distributed via a TCP/IP network to the MMI computers both locally and remotely. The PI also used the database as a very simple mechanism to send data from one MMI to another by writing commands into the database. This allowed them to completely concentrate on the development of their MMI without having to spend time on writing any software for network communication.
A small Gamma application, based on one of the examples provided by Cogent, was developed to work as a Telemetry simulator. This application was feeding the database with random data, which was very useful for the PI team during development of their MMI.
The system worked very well, and all parties involved were very pleased with the functionality provided by the Cascade DataHub. There were some initial problems of using Cascade Connect together with LabView, but this was easily solved with the excellent help from technical staff at Cogent.
Since the Cascade DataHub is completely configurable (even at run-time), the developed system can be reused for future missions without any modifications of the QNX system.
For any application which needs to do real-time data collection and distribution, the DataHub is the obvious choice.