A PC-based data acquisition system supervisor [for wind tunnel tests]

CIRA\´s "Instrumentation and Data Acquisition" group has developed an application software, working on a distributed environment, to automate the repetitive wind tunnel tests and to control the data acquisition process and visualise the data, from locations remote to the control room. Pressure acquisition subsystems of the CIRA transonic wind tunnel (PT-1) have been integrated, co-ordinated and controlled by software modules running on different PCs operated by Windows 95/NT. A software module called "Server", running on a local PC (Controller) which directly interacts with the electronic device through the relevant hardware interface, receives and sends messages for configuration & control. Each controller works as a server and export data by a DataSocket Server. A software module called "Integrator", running on a remote PC and connected to the controller PCs through a LAN link, works as client of the different servers from which receives messages containing information about subsystems. The integrator co-ordinates the operations of subsystem configuration, configuration upload, calibration, data acquisition, data recording and data visualization. The integrator can automate the entire process for pitch&pause or pitch sweep tests using a software mechanism to trigger the data recording at the achievement of a specified condition configured by the operator. The communication between client and servers is implemented by means of TCP/IP messages. One more module, called "Viewer", allows the user to have a real-time display of the acquired data in the format he prefers: numerical display, time history or histogram (a way to represent a group of channels simultaneously to show, for instance, pressure distributions). Different sets of data channels can be showed by different instances of the viewer running concurrently on the same PC or on different PCs located remotely to the data servers (customer offices) and connected to the LAN