Display

Description

Using the display functions it is possible to output texts to the front display of the controller with the functions FC_DisplayLineWrite() and FC_DisplayMessageWrite(), or to delete characters from the display with the functions FC_DisplayClear() and FC_DisplayClearLine(). For this purpose, a specific mode is available (ET_DisplayModeSelect.IecMode), which can be activated by using the function FC_DisplayModeSet().

In the default setting, the system is in DISPLAY_SYSTEM_MODE. In this mode, only the PacDrive firmware has write access to the display. The currently set mode can also be queried by using the function FC_DisplayModeGet(). During a program reset, the mode setting switches automatically to standard mode.

If the display is not modified during the call, that is, if a write function is called but the text does not differ from the text shown on the display, the text on the display is not affected and the functionFC_DisplayRefreshed() immediately returns the value TRUE.

The display functionality of the controller may only be used after the boot process of the controller has been completed.

With the boot process completed, the output is effected asynchronously to the task calling. If the display functions are already called in advance (FC_GetPacDriveBootState() = 0), a synchronous output is effected. This means that the task is decelerated for the duration of the processing time of the display output. Due to slow processing, this may take up to one second in the case of the controllers.

The following functions are affected:

• FC_DisplayClear()

• FC_DisplayClearLine()

• FC_DisplayLineWrite()

• FC_DisplayMessageWrite()

• FC_DisplayModeSet()

• FC_DisplayRefreshed()

Example

 PROGRAM SRC_Display 
VAR 
   diState : DINT := 0;  (*State*)
   sDisplayMessage : STRING(80) := 'Test';  (*display-message*)
   diResult : DINT := 0;  (*Result of the display functions*)
   diResultDisplayRefreshed : DINT := 0;  (*Result of the DisplayRefreshed-function*)
   xDisplayStatus : BOOL := FALSE;  (*Display refreshed?*)
   xError : BOOL := FALSE;  (*Error*)
   xEnableWriteDisplayMessage : BOOL := FALSE;  (*enable writing the DisplayMessage*)
   xEnableClearDisplay : BOOL := FALSE;  (*enable clearing the display*)
END_VAR 
CASE diState OF 
0 :  (*Wait on PacDrive Controller ready*)
   IF FC_GetPacDriveBootState()=1 THEN 
      diState := diState + 1; 
   END_IF; 
1 :  (*Wait on user input*)
   IF xEnableWriteDisplayMessage THEN 
      diState := diState + 1; 
   END_IF 
   IF xEnableClearDisplay THEN 
      diState := diState + 1; 
   END_IF 
2 :  (*Actual Display-mode?*)
   IF (FC_DisplayModeGet() = ET_DisplayModeSelect.IecMode) THEN 
      diState := diState + 2; 
   ELSE 
      diState := diState + 1; 
   END_IF 
3 :  (*Switch on IEC-Mode*)
   IF( FC_DisplayModeSet(ET_DisplayModeSelect.IecMode) = 0) THEN 
      diState := diState + 1; 
   END_IF 
4 :  (*Write or Clear Display*)
   IF xEnableWriteDisplayMessage THEN 
      diResult := FC_DisplayMessageWrite(1, 1, sDisplayMessage, TRUE); 
      xEnableWriteDisplayMessage := FALSE; 
      diState := diState + 1; 
   END_IF 
   IF xEnableClearDisplay THEN 
      diResult := FC_DisplayClear(); 
      xEnableClearDisplay := FALSE; 
      diState := diState + 1; 
   END_IF 
5 :  (*Display refreshed?*)
   diResultDisplayRefreshed := FC_DisplayRefreshed(xDisplayStatus); 
   IF( (diResultDisplayRefreshed = 0) AND ( xDisplayStatus = TRUE) ) THEN 
      diState := diState + 1; 
   END_IF 
6 : IF(diResult <> 0) THEN 
      xError := TRUE; 
      diState := 10; 
   ELSE 
      diState := 1; 
   END_IF 
10:  (*error state*)
   ;  (*do nothing*)
END_CASE