# The TAS Client

The TAS client is the dedicated SICS client for the triple axis spectrometers. It allows both to control the instrument and to view its current status.

## Step 1: Starting the TAS Client

On the LNS unix systems the TAS client can be started by typing:

    tas &

at the unix command prompt. For PC's and proper Macintosh computers (proper is MacOS > 10) the recommended way to start the TAS program is to install Java Web Start and run it from the SICS Java Web Start page. Further instructions and the applications can be found at: http://lns00.psi.ch/sics/wstart .

## Step 2: Connect to an Instrument

Due to the client server architecture, the client program alone is only of very limited use. In order to become usefule, a connection to a SICS server has to be established. The obvious way to do this is through the menu selections in the Connect menu of the TAS client. There are various entries for various triple axis spectrometers and their simulation programs. With the Custom Connect option the connection parameters, the computer running the SICS server and the server port where the SICS server listens, can be entered manually. This is only necessary when SICS had to be relocated due to a hardware outage.

## Step 3: Use The TAS Client

The TAS client consists of a menubar, a row of buttons beneath and a central activity area. The central activity area can display three different sub panels. These sub panels are selected through the buttons underneath the menubar. The following sub panels are available:

- A Command Panel for entering commands.
- A Status panel displaying the current values of interesting instrument parameters, most notably the positions of the 6 magic triple axis motors.
- A Plot panel showing the data collected in the currently running scan and some auxiliary information about the scan.

At the very bottom of the screen is a yellow line displaying the current status of a pending counting operation. Below that is a text line displaying the current status of the instrument.

### The Command Panel

The command panel consists mainly of a text area in which the communication between the TAS client and the SICS server is logged. A text entry field at the bottom serves to enter commands to the SICS server. The little red button, labelled Interrupt, besides the text entry field can be used to interrupt the currently running measurement.

The Command Panel has a menu associated with it. Through this menu logging to a file can be enabled. This log file is written locally on the machine running the TAS client. Submenu entries are available for opening and closing such log files. SICS has various levels of user rights. When connecting to the SICS server you are logged in with lowest possible privilege. In order to change your privilege, enter a username and a password through the Command/User Rights dialog.

### The Plot Panel

The Plot Panel displays the data collected in the current scan. This display is automatically updated as soon as new data becomes available through the progress of the scan. You may zoom in on details in th plot by dragging a rectangle enclosing the interesting region from top to bottom. You may zoom out by dragging a rectangle from the bottom to the top.

## Step 4: Closing the TAS Client

You can exit the TAS client through the File/Exit menu entry. You can also disconnect from the current SICS server through the Connect/Disconnect option and connect to another SICS server through the menu choices provided.