14.22. Common: Sending Commands to the Cascade Historian send_hs_command, assign_history, display_hs_info

These functions are located in the lib/common.g file.

   /*--------------------------------------------------------------------
    * Function:    send_hs_command
    * Returns:     The return from the Cascade Historian,  or nil
    * Description: Sends commands to the Cascade Historian.
    *------------------------------------------------------------------*/
   function send_hs_command(widget, purpose, pt, args)
   {
     local tsk, arg0, arg1, arg2, arg3, ret1, ret2;
   
     /* Choose the correct history, based on the point name. */
     local pt1 = parse_string(string(substr(string(pt), 0, 3), "DB"));
     local pt2 = parse_string(string(substr(string(pt), 0, 3), "DBP"));
     
     if ((tsk = locate_task("demohistdb", nil)) != nil)
       {
         switch (purpose)
           {
           case "enable":
             if (widget.switched_on())
               ret1 = send(tsk, `enable());
             else
               ret1 = send(tsk, `disable());
           case "deadband":
             arg0 = string("(absolute ", args[0], ")");
             arg1 = string("(percent ", args[1], ")");
             arg2 = string("(timelimit ", args[2], ")");
             arg3 = string("(countlimit ", args[3], ")");
             ret1 = send(tsk, `deadband(@pt1, @arg0, @arg1, @arg2, @arg3));
             ret2 = send(tsk, `deadband(@pt2, @arg0, @arg1, @arg2, @arg3));
   
             /* Print the return values. */
             princ("Deadband status for ", pt1, ":\n", ret1, "\n");
             princ("Deadband status for ", pt2, ":\n", ret2, "\n");
           case "version":
             ret1 = send(tsk, `version());
             ret1;
           }
         close_task(tsk);
       }
     ret1;
   }
   

   /*--------------------------------------------------------------------
    * Function:    assign_history
    * Returns:     A string
    * Description: Changes the point-name suffix (_001) of a history to match
    *              the corresponding deadbanded history.  Called by the
    *              .assign_values() function, which selects the proper
    *              history based on the Y history and X history drop-down
    *              boxes in the GUI.
    *------------------------------------------------------------------*/
   function assign_history(dbset, history, entry)
   {
     switch (dbset)
     {
           case "NONE":
             history = entry;
           case "DB":
             history = string(substr(entry, 0, 3), "DB");
           case "DBP":
             history = string(substr(entry, 0, 3), "DBP");
     }
     history;
   }
   

   /*--------------------------------------------------------------------
    * Function:    display_hs_info
    * Returns:     An integer (50)
    * Description: Puts the Cascade Historian version number and instructions
    *              into the text widget.  Used only at start-up.
    *------------------------------------------------------------------*/
   function display_hs_info(txt_wgt)
   {
     local version_string;
     for(i=0; i<=50; i++)
       {
         if ((version_string = string(send_hs_command(nil, "version", nil, nil))) != "nil")
           {
             anygui_show_text(txt_wgt,
                              string("Now running ", substr(version_string, 9, 17), "\n",
                                     substr(version_string,
                                            27, strstr(version_string, "at") - 27),
                                     "\n\nTo start the demo, ensure that\nthe PID Emulator ",
                                     "is running,\nthen press the Record button."),
                              3);
             i = 50;
           }
         else
           usleep(10000);
       }
   }