### The device rack

The devices rack is lowest (deepest) layer from the final (graphical) presentation point of view. This layer is shown on the right of your screen where each virtual device is presented as separated "child" window into the device container window (device rack). The user can control each device manually and see the results from measurements. There are three types of devices – measurement (MD), control (CD) and synchro types. Synchro (short from synchronization) device is only one, but another two types could be as many as needed. One could say that measurement device is input device and control device is output one and that would be no far from the truth (see Glossary for definitions). Each type provides standard set of commands called by the interpreter. Your real (external) devices are presented by these "logical" devices the same way as in "good old" DOS you can assign a directory to logical drive. One real device could be presented by more than one logical device. If the external device is really complex and has both measurement and control functions, the only way to "plug" it into the Spectrion is to present it as two logical devices - one for the control functions and one for measurement ones. Each logical device (device for short) is presented in Spectrion in two ways. First way is visual, in separate window (form in Delphi) with visual components, which represent different device features. There, the user can operate manually with these features, setting for example the most appropriate parameters for the next measurement.

Each device has in four states:

- off-line (white-cream banner) – before initialization (connection)
- standby (grey banner) – after initialization, but not running yet
- running (teal banner) – working state
- warning (yellow banner)– as running but with warning that one or more of controlled parameter are out of range.
- danger - the device goes in standby state due to a dangerous conditions

To understand better what measurement or control devices are follow the three lists of commands which define internal interface between interpreter and device in Appendix B.

Each device has three pages (tabs) –

- Normal page for minimised presentation of device functionality - minimum space, without lost of control or information.
- The purpose of extended page is visual comfort. Each functionality of a device is presented by full colour visual components, for easy manipulation (e.g dials, sliders) and nicer signal visualization (e.g. charts, progress bars).
- Third page is for opening/saving or some adjustments of the device setting. Each saved device setting file has an extension of the device name (three charatcters). When initialized the device (e.g. DVC) would look for Defaults.DVC file to load its setting from.

On the top of device rack there are some buttons to operate it. The green long button on the right is the main switch (of the device rack). On the left next is lock/unlock button to enable/disable user control to the devices, next two buttons are for loading/saving the device rack setting (complete set of all devices settings), and the last three buttons allows the user to turn all the device pages simultaneously.

There are two modes of synchronization synchro mode and asynchro mode. In the synchro mode the pointer of the data buffer is transferred into the measurement device and then that device is taking care for synchronization – usually immediately after the measurement is done the buffer is updated. That is so called Data stream mode, (fastest possible) with sacrifice of control – nothing else could be changed synchronically. Visually it is presented by redish small panel under the synchro device. In asynchro mode the synchronization of the measurement is done by synchro device, each time the measurement needs synchronization the procedure takes it from there. The possible ways to synchronization are: by button, delay or external event.