NAME
        CMD_STOP  - Stops the device.
   SYNOPSIS
        Standard device command.
   FUNCTION
        CMD_STOP halts the currently active speech (if any) and prevents
        any queued requests from starting.
   INPUTS
        Valid iorequest block with the io_command field set to cmd_stop.
        A valid iorequest block is one with its io_message structure, and
        io_Device and io_Unit fields properly initialized.  The easiest
        way to insure proper initialization is to make a copy of the
        iorequest block after a successful opendevice call.
   RESULTS
        io_Error set to 0.
   SEE ALSO
        Exec input/output documentation.