Short summary

Name	`SysTaskActualCycleTime`
→POU type	→function
Category	more system blocks, blocks for target-system diagnostics, block with internal error diagnostic
Graphical interface
Available since	version 1.46.0 (for logi.CAD 3) and version 2.3.801 of the →runtime system This block is supported for these →target systems or platforms: →Econ 100, →MICA, →phyBOARD-Regor, →phyBOARD-Wega, →Raspberry Pi, →Revolution Pi, →µMIC.200 platform `WindowsX86` (incl. the built-in PLC under Windows) version 1.109.0 (for logi.CAD 3) and version 3.19.0 of the →runtime system This block is supported for these →target systems or platforms: →phyBOARD-Regor, →phyBOARD-Wega, →Raspberry Pi, →Revolution Pi platform `WindowsX86` (incl. the built-in PLC under Windows) platform `LinuxX86` →Econ 100 (only up to version 3.2.0 for logi.CAD 3) →µMIC.200 (only up to version 1.126.0 for logi.CAD 3)

Functionality

The block returns the actual cycle time of the previous execution of the →task in the context of which the block is called.

The block requires up to 3 cycles in order to determine the cycle time. Hence, the return value is correct only with the 4th cycle onwards.

Return value

	Identifier	→Data type	Description
Return value:	–	`TIME`	the actual required cycle time for the execution of the application (the generated code)

Input EN and output ENO are available when →calling the block. See "Execution control: EN, ENO" for information on input EN and output ENO.

See:

"Blocks for safe logic" whether this block is supported for developing safety-relevant applications.
"Highlighting safe logic in the FBD-editor" for the effects when using the block as a block for safe logic .

Internal error diagnostic for block

If the required information is not provided by the PLC, the output ENO of the block is set to value FALSE (or an equivalent).

Example for usage within ST-editor

FUNCTION_BLOCK TestSysTaskActualCycleTime
	VAR
		actual : TIME;
		okActual : BOOL;
		cycle : INT := 1;
	END_VAR
	
	IF cycle > 3 THEN			(* SysTaskActualCycleTime needs three cycles to determine the correct cycle time*)
		actual := SysTaskActualCycleTime(ENO => ENO);
		(* Function 'SysTaskActualCycleTime' returns the actual cycle time. *)
		okActual := actual > T#450ms AND actual < T#550ms;
		ENO := AND(ENO, okActual);
	END_IF;
	
	cycle := cycle + 1;
END_FUNCTION_BLOCK

When creating your application within the ST-editor, enter a call of a block by typing the text as requested by the syntax or use Content Assist.

Restriction for test framework

Do not use this block within a POU under test (see "Testing single POUs by using the test framework") because this block is not supported when a test is executed. Reason: The cycle time is adjusted during the test execution so this block returns faulty data.