## The Token Command

In SICS any client can issue commands to the SICS server. This is a potential source of trouble with users possibly issuing conflicting commands without knowing. In order to deal with this problem a "token" mechanism has been developed. In this context the token is a symbol for the control of an instrument. A connection can grab the token and then has full control over the SICS server. Any other connection will not be privileged to do anything useful, except looking at things. A token can be released manully with a special command or is automatically released when the connection dies. Another command exists which allows a SICS manager to force his way into the SICS server. The commands in more detail:

token grab
  Reserves control over the instrument to the client isssuing this command. Any other client cannot control the instrument now. However, other clients are still able to inspect variables.
token release
  Releases the control token. Now any other client can control the instrument again. Or grab the control token.
token force password
  This command forces an existing grab on a token to be released. This command requires manager privilege. Furthermore a special password must be specified as third parameter in order to do this. This command does not grab control though.