Problem(s) Encountered:

Dome slit and dropleaf controls are not responding.

The error message is  ERROR: Could not send command. Socket is not connected.

Solutions:

The rslit task had stopped.  Quit the TCS GUI; in a terminal window type telescope status to see if any servers are stopped.  Type telescope stop to stop all servers; type telescope start to restart them.  Open the GUI, initialize and control of the dome shutter systems returned.  It may be prudent to restart JSkyCalc and time the telescope servers are cycled.