Description

Function description

The function is to "freeze" the sequence (evaluation of transitions is turned off).

WARNING

UNEXPECTED SYSTEM BEHAVIOR

Do not use FREEZECHART 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.

The current state of the sequence is frozen by a 1 signal at the input FreezeSequence. The status of the transitions is no longer evaluated. Therefore, it is no longer possible to move on in the sequence, even if the transition condition of the "active" transition is true.

This function can be used in conjunction with the functions for step-by-step processing (function block SFCCNTRL (Inputs STEPUN and STEPDEP) or external SFC control command) for error correction.

The output SequenceFreezed is 1 when the sequence is frozen.

NOTE: The output shows the current status of the sequence, i.e. the sequence can also be frozen with the function block SFCCNTRL or another external SFC control command.

EN and ENO can be configured as additional parameters.

Representation in FBD

Representation in LD

Representation in IL

Representation:

LD SectionName
FREEZECHART SectionName
ST SequenceFreezed

Representation in ST

Representation:

SequenceFreezed := FREEZECHART (SectionName,
                                 FreezeSequence) ;

Parameter description

Description of the input parameter:

Parameter	Data type	Meaning
`SectionName`	`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.)
`FreezeSequence`	`BOOL`	1: Freeze sequence (turn off evaluation of transitions)

Parameter

Data type

Meaning

SectionName

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.)

FreezeSequence

BOOL

1: Freeze sequence (turn off evaluation of transitions)

Description of the output parameter:

Parameter	Data type	Meaning
`SequenceFreezed`	`BOOL`	1: Sequence was frozen (evaluation of transitions was turned off)