Description

Function description

This function is to reset sequences.

WARNING

UNEXPECTED SYSTEM BEHAVIOR

Do not use CLEARCHART to find error on controllers of machine tools, process or material management system if they are running.

Failure to follow these instructions can result in death, serious injury, or equipment damage.

WARNING

UNINTENDED EQUIPMENT OPERATION

Avoid using SFCCNTRL command with CLEARCHART, FREEZCHART, INITCHART, SETSTEP and RESETSTEP commands altogether.
Carefully check the interactions between these function blocks and analyze the resulting impact on SFC.

Failure to follow these instructions can result in death, serious injury, or equipment damage.

With a 1 signal at the input ClearSequence, the sequence is stopped and all steps are reset. As long as the 1 signal is at the input, the sequence stays in this mode, i.e. it cannot be started.

This state remains even if input ClearSequence reverts back to 0.

The status (sequence reset) is shown with a 1 signal at the output ClearState.

Only when there is a 0 signal at the input ClearSequence, the sequence can be started with the function block SFCCNTRL (Input INIT), the function INITCHART or another external step activation command.

Since the sequence is permanently reset as long as there is a 1 signal at the input ClearSequence, you should take the following measures to prevent a permanent blocking of the sequence:

Conditional call of the function CLEARCHART via the input EN.
Conditional call of the function CLEARCHART via e.g. IF statement in the programming language ST.
Use edge recognition (R_TRIG) at the input ClearSequence.

NOTE: The output ClearState shows the current state of the sequence, i.e. the sequence can also be reset with the function block SFCCNTRL (Input CLEAR), the function INITCHART, the procedure RESETSTEP (reset the last/only active step) or and other control command (external).

EN and ENO can be configured as additional parameters.

Representation in FBD

Representation in LD

Representation in IL

Representation:

LD SectionName
CLEARCHART ClearChart
ST ClearState

Representation in ST

Representation:

ClearState := CLEARCHART (SectionName, ClearChart) ;

Parameter description

Description of input parameters:

Parameter	Data type	Description
`CHARTREF`	SFCCHART_STATE	Association with the SFC section to be controlled is done via the name of the section. If an SFC section is created then it is automatically assigned with a variable of data type `SFCCHART_STATE`. The variable that is created always has the name of the respective SFC section.)
`CLEAR_I`	`BOOL`	0->1: Reset all active steps in the sequence.

Parameter

Data type

Description

CHARTREF

SFCCHART_STATE

Association with the SFC section to be controlled is done via the name of the section.

If an SFC section is created then it is automatically assigned with a variable of data type SFCCHART_STATE. The variable that is created always has the name of the respective SFC section.)

CLEAR_I

BOOL

0->1: Reset all active steps in the sequence.

Description of output parameters:

Parameter	Data type	Description
`CLEAR_O`	`BOOL`	1: Sequence was reset, i.e. the sequence has no active step