# Program Invocation

SICS is a client server system. This means there must be a server running somewhere as a prerequsite for SICS operation. This server program lives on the instrument computer. To check for its existence you need to log on to that computer and execute the command: CheckSICS. If this test fails to find the server, it can be started by typing TOPSIServer at that computer. Please note, that this has to happen as Instrument user ( for example TOPSI) on the instrument computer.

The SICS clients are the programs a user interacts with. Their main purpose is to forward commands to the server and to display the answers. A client also implements the status display. Various clients exist for different platforms.

## Accessing SICS through Telnet

SICS is able to communicate with standard TCP/IP telnet clients. Suitable telnet clients are available on allmost all computer platforms free of charge as part of the network software. In order to access SICS with telnet you need to know the following five bits of information:

- The name of the computer where the SICS server is running.
- The port number at which the SICS server lsitens for telnet connections.
- The login word.
- A valid username.
- A valid password for your user name.

This information will be supplied to you by your instrument scientist if she finds you and your cause honorable enough.

Loging in to SICS through telnet requires the following steps:

- Invoke your telnet client and try to contact machine name at the port number given. For example on a Unix or VMS this looks like:

           telnet machine.psi.ch 7654

  Of course this may differ if you use a telnet client on a different platform.
- If things go well, you'll be connected to the SICS server then, though he does not tell you about it. However, SICS will not allow you to type commands yet. You have to login with the magic three words: loginword username password. Only if you get this right, the SICS server will print a welcome message and you may type commands to the server.

You can logoff from the SICS server by typing logoff.

## TOPSI Client Program Invocation on Digital Unix

On LNS DigitalUnix systems the command topcom will start a command line client. Even this is an X11 application. If it fails to start, make use the DISPLAY variable is properly set. If not type:
setenv DISPLAY YourComputer.psi.ch:0.0
replacing the YourComputer bit with the name of your machine. Once started up, dmccom shows a menubar, a large list window at the top, a smaller one below, followed by an edit field and a row of buttons at the very bottom. At the left lower corner that is a red field which should say: Disconnected. This is a status display. In order to make topcom usable a connection to the server needs to be established. This can be done by clicking at the TOPSI entry in the Connect menu. Please allow some time for the establishment of the connection. Once this is done, the status display at the bottom will change to the current status of the server. Now commands can be typed into the edit field at the bottom. The response of the server will be displayed in the top listbox. The lower listbox will hold a history of commands typed. Commands in this list can be reinvoked by double clicking them. By clicking on them with the right button they can be copied into the edit field for editing.

A status display for TOPSI can be started by typing topstat.