Concept V2.5

Lesson 19 Objectives:After completing this lesson, the learner will be

able to:– Program control logic using the Sequential Function

Chart Editor.– Test the processing of a Sequential Function Chart

section using the Animation Panel.– Identify the components of a Sequential Function

Chart.» Step

» Transition

» Jump

» Branch

Up Limit SW

Slow Speed Limit SWBottom Limit SW

Up Limit SW

Slow Speed Limit SWBottom Limit SW

Up Limit SW

Slow Speed Limit SWBottom Limit SW

Up Limit SW

Slow Speed Limit SWBottom Limit SW

Wait

Up Limit SW reached

Lower Fast, drill motor on

Start Pushbutton Pressed

Lower Slow, drill motor on

Slow Speed Limit SW reached

Raise Drill, drill motor on

Bottom Limit SW reached

Start

Start

Start

Start

Concept V2.5

Lower_Fast.x OR_BOOL

Lower_Slow.x

Raise_Drill.x

Drill_Motor_on

Lower_Fast.x AND_BOOL Drill_Lower_High_SpeedTRUE

Lower_Slow.x AND_BOOL Drill_Lower_Slow_SpeedTRUE

Raise_Drill.x AND_BOOL Drill_RaiseTRUE

FBD LDLower_Fast.x

Lower_Slow.x

Raise_Drill.x

Drill_Motor_on

Lower_Fast.x Drill_Lower_High_Speed

Lower_Slow.x Drill_Lower_Slow_Speed

Raise.x Drill_Raise

Concept V2.5

Drill Press Output Control

Supply Hopper

Loader

Rotation

Drilling

Clamping

12 3

4

50

Tester

Evacuation

Rotary Table Application

Concept V2.5

Rotated LSW

Rotate Plate

True (1)

Initialization

Start & Initial Cond

Loader Ext & Part Pres

Loader Retracted LSW

Loader Advances

Loader Retracts

Wait

Loader Sequence

Clamp extended LSW

Drill Lowered LSW

Drill Raised LSW

Clamp retracted LSW

Clamp Advances

Drill Lowers

Drill Raises

Clamp Retract

Wait

Drill Sequence

Rotary Table SFC Control

Gage Lowered

Gauge Raise

Unloader Advanced

Unloader Retracted

Wait

Error Raise Gauge

Wait for Operator

Gauge Down LT 5s

Gauge Raised LSW

Unloader extended LSW

Unloader retracted LSW

Gauge Down GTE 5s

Gauge Raised LSW

Manual Reset Pushbutton

Test & Eject Sequence

Concept V2.5

Concept V2.5

What is SFC? Sequential Function Chart

A Sequential Function Chart is a graphic method of representing a sequential control system by using a sequence of steps and transitions.

Each step is a command or action that is either active or inactive.

The flow of control passes from one step to the next through a conditional transition that is either true or false.

Transition Jump

S_2_1

Step

S_2_1

Parallel Branch

Parallel Joint

Alternative Branch

Alternative Joint

Concept V2.5

SFC - Elements

1. A Sequential Flow Chart section

must have an Initial Step and

only one Initial Step.

2. A Transition must follow a Step.

3. A Step must follow a Transition.

Concept V2.5

SFC Rules

Concept V2.5

SFC - Elements: The Step

Step types are the initial step or steps.

A step becomes active when the prior transition has been satisfied

A step becomes inactive when the succeeding transition has been satisfied AND the step delay time has elapsed.

None, one or multiple actions, with qualifiers, can be declared for each step.

A supervision time can be defined for each step.

Concept V2.5

Step type:Step or initial stepOne initial step per section must be defined in

each sequential chain This initial step starts the sequence when

initializedIt is marked with double lines along its margins

Concept V2.5

Step Name (IEC Like)

The step name is automatically generated and can be edited (free names)

The default for steps and transitions is the IEC Like naming.

A step name must be unique throughout the entire project

Step name length: maximum 32 characters

The automatically generated step name always has the structure: S_n_m

• S = step

• n = number of section (consecutive number)

• m = number of step in the section (consecutive number)

Concept V2.5

Step Name (Dynamic Numbered)

Instead of free names, alias names can be selectedfor steps (and transitions):

Structure of alias names: S_nn_sszz• S = step• n = first characters of section name (number

of characters selectable)• ss = Branch number on the section• zz = Step number in a branch

Choosing the alias can be activated in Options > Preferences > Graphical Editors...

Concept V2.5

Step name (Dynamic names) Example

Concept V2.5

SFC - Elements: The TransitionA transition is the condition that transfers

control from one step to another. Only transitions following active steps are

solved / evaluated.When a transition is True on the next scan:

• The preceding step(s) is deactivated

• The following step(s) is activated

• The True transition between the steps is no longer solved

• The transition following the new active step is solved

Var_Lit_Dir

Trans_Sect

Concept V2.5

A transition is a single control object of data type BOOL and can be:

a direct address

a variable

a literal (0 / FALSE or 1 / TRUE)

a transition section.

Concept V2.5

Transition sections are special sections that have:

One single BOOL output

Its output name is the same as the transition section name.

Only one section per transition

Only functions, no function blocks can be used.

Concept V2.5

Transition Sections:

will be automatically created when opened.

can be created for every transition.

can be programmed in FBD, LD, IL or ST.

In FBD the section automatically pre-assigns an AND_BOOL function with the following:

• one output, preassigned the actual name of the transition section

Concept V2.5

SFC - Elements: The JumpThe jump allows the program to

continue from a different location.

A jump can be used in two ways:• sequence jump

• sequence loop

Jumps into or out of a parallel sequence area are not possible.

Sequence-Loop

Sequence-Jump

S_6_3

S_6_4

S_6_5

S_6_3

SimpleLoop

S_6_1

S_6_1

S_6_2

S_6_6

S_6_7

S_6_8

S_6_8

Concept V2.5

The Jump

Alternative Branch

Alternative Joint

Concept V2.5

SFC - Elements: Alternative Branch The alternative branch offers

conditional programming ofbranches in the control flow ofthe SFC structure.

There can be only one branchactive at a time

Left-to-right priority

All alternative branches mustbe joined back into one singlebranch using alternative jointsor jumps.

Concept V2.5

Alternative BranchExample:Alternative

sequences

Concept V2.5

SFC - Elements: Parallel Branch Parallel branches split up the processing

into two or more sequences.

One common transition directly above theparallel branch is allowed.

The sequences are processed in paralleland are processed independently of eachother.

The parallel joint combines two or moreparallel branches to form one branch.

One common transition is directly belowthe parallel joint.

• This transition is evaluated only whenall directly preceding steps of the transitionhave been set.

Parallel Branch

Parallel Joint

Concept V2.5

Example:

Parallel sequences

Select modeSelect column mode

Select row modeStep creation mode

Transition creation modeParallel branch creation mode

Parallel joint creation modeAlternative branch creation mode

Alternative joint creation modeJump creation mode

Link creation mode

Concept V2.5

Text creation mode

Toggles animation mode

Toggles presentation of animation panel

Step-Transition sequence creation mode

Structured parallel component creation mode

Structured alternative component creation mode

Transition-Step sequence creation mode

Concept V2.5

Concept V2.5

Fast creation of Elements

Concept V2.5

SFC Development

Create a new SFC section.

Create sequence with SFC elements.

Define step properties.

Define transition condition.

Concept V2.5

SFC Programming

Concept V2.5

Step Actions

A step can be assigned none, one or multiple actions.

An action is a BOOL variable or direct address.

An action can be assigned a qualifier.

Concept V2.5

Step Programming

Concept V2.5

Qualifiers N None, action is active when the step is active. S Set of the action (1), remains active even if

the step becomes inactive (saved/stored) R Reset of the action (0) L Time limited set of the action during the step

active period D Action will be delayed active during the step

active period. P Set of the action for one program scan (pulse) DS Delayed set of the action

Step Activity

Step

QualifierN,NONE

S

R

L

D

P

DS

10

10

10

10

10

10

10

10

Step active

Concept V2.5

Actions, Qualifiers Timing Diagram

Var_Lit_Dir

Concept V2.5

The Transition Variable (Literal, direct address)

Trans_Sect

Concept V2.5

The Transition Section

contains the logic of the transition condition as well as being automatically linked to the transition.

Concept V2.5

The Transition Section

Modify, extend with functions, links

....close section

Concept V2.5

The Transition Section

Transition is activated if variable is TRUE (e.g. S_17 = TRUE)

Normal View Expanded View

Concept V2.5

View: Normal / Expanded

Concept V2.5

Transition section is not in operation

Transition is not satisfied (monitored)

Transition is satisfied (monitored)

Black

Red

Green

Animation of the Steps In a running Quantum PLC, the displayed data is

automatically updated. If it has stopped, the static state of the program is displayed from the Quantum PLC.

Concept V2.5

Step is inactive

Step is active

Time over rangeThe error display terminateswhen the step becomes inactive.

Time under rangeThe error display remainseven though the step has been inactivated.

White

Magenta

Green

Yellow

STEP_17

123s340ms

Concept V2.5

Displays the time that has passed sincethe step became active.The time display in active steps is updated

continuously.After the step has become inactive, the time

display is maintained until the next activation of the step. Each time the step becomes active, the old time is reset and time begins from 0.

Green

Concept V2.5

Supervision timesMaximum supervision time:

• If the step is still active after this time has expired, a bit is set and in animation mode there will be an error message and a color change of the step

• must be greater than the minimum supervision time and the step delay time.

Minimum supervision time:

• If the step becomes inactive before this time has expired, a bit will be set and in animation mode there will be an error message and a color change of the step

• Must be smaller than the maximum supervision time and greater than the step delay time.

Magenta

Yellow

Concept V2.5

Supervision timesStep delay time:

• Defines the active step time, i.e. the minimum length of time the step will remain active.

• Must be less than maximum and minimum supervision time.

Entry of Supervision and Step delay time:• as literal (direct, fixed values) or as• Variable of Data type SFCSTEP_TIMES:

– select SFCSTEP_TIMES Variable Variable Declaration... enter Variable name Data type SFCSTEP_TIMES Set... value Step properties enter name of SFCSTEP_TIMES typed variable

Concept V2.5

Entry of Supervision times

Concept V2.5 Entry of Supervision times

Concept V2.5

Entry of Supervision times

Concept V2.5

Learning Mode Supervision timesLearning Mode for automatic determination of

supervision times is possible after "Connect" and "Download":

Online Menu Animate SFC section Animation Panel Learning Mode On Waiting ..... Learning Mode Off Continue/Accept

Concept V2.5

Learning Mode Supervision times

Concept V2.5

The Step VariableEach step is implicitly (automatically) assigned a (read only)

variable from data type SFCSTEP_STATE. This step variable has the same name as the step.The step variable can be used everywhere as FFB input to

ask for the status.The step variable has the following structure:

• “Stepname”: SFCSTEP_STATE• t: TIME• x: BOOL• tminErr: BOOL• tmaxErr: BOOL

Concept V2.5

The Elements have the following meaning: ’Stepname’.t Current retention time in the step

’Stepname’.x 1: Step active0: Step not active

’Stepname’.tminErr 1: Low limit violation of minimum supervision time0: No low limit violation of minimum

supervision time

’Stepname’.tmaxErr 1: Upper limit violation of maximum supervision time0: No upper limit violation of maximum supervision

time

Example for stepname = STEP_1:

STEP_1.t Current retention time in STEP_1

Concept V2.5

Animation panelThe animation panel allows you

to test the processing of an SFC section. For example, steps can be commutated, the processing of the sequence can be controlled (whether transitions or actions are to be processed), time errors can be reset or the sequence can be reset to the initialization state.

The animation control panel provides all available operator options in a dialog box.

SFC-Section animated, Online, Animation panel

Concept V2.5

Animation panel Section

• The name of the SFC section that the dialog box is active for is displayed here.

Processing Parameters: SetResetFlag

• To reset the sequence, you must activate SetResetFlag. This will stop the sequence and all actions will be reset. Operator interventions are not possible.

• To start the sequence, you must first activate and then deactivate SetResetFlag. The 1 > 0 edge will reset the sequence, i.e. the initial step is activated.

DisableTimeCheck

• If activated, step time supervision is no longer performed.

Concept V2.5

Animation panelDisable Transitions

• If activated, the states of the transitions are no longer analyzed. The sequence remains in its current state, regardless of the signals on the transitions. Operation of the sequence is only possible with the control commands SetResetFlag, StepUnconditional, StepTransDependent.

Disable Actions• If activated, the actions of the steps

are no longer processed.

Concept V2.5

OperationsStepUnconditional

• Regardless of the state of the transition, the next step will be activated, but not until the Step delay time of the active step has expired.

• In parallel branches, StepUnconditional will always activate every branch

• In alternative branches, it will always activate the left branch.

• Use StepTransDependent for process dependent activation of branches.

Concept V2.5

Further Operations StepTransDependent

• When the transition condition is satisfied, the next step will be activated.

• StepTransDependent is only recommended for an active DisableTransitions.

• By freezing the transitions (DisableTransitions), StepTransDependent allows you to manually process the elements of the sequence step by step. Dependent on the transition condition, the transitions proceed.

ResetTimeErrors

• If ResetTimeErrors is activated, the display of the error messages of the time supervision in the SFC section will be reset.

Concept V2.5

Further Operation ForceSelectedStep(s)

• Independent of the state of transitions and steps, the selected step(s) is activated.

• In alternative branches, only one single step can be activated.

• In parallel branches, exactly one single step per parallel branch must be activated.

Warning: ForceSelectedStep(s) is not recommended for an error

search with controllers of machine tools, processes or materials maintenance systems while they are running.

Since logic processing is no longer taking place, the Quantum ignores all input information. This might result in unsafe, dangerous, and destructive operations of the tools or processes that are connected to the Quantum controller.

Concept V2.5

Further Operation Learning mode ...

see "Supervision time..."

Select active Step(s)The active step at this moment will be

marked on the section

RESETTIME

TRANSACT

MODECHGSTATECHG

TIMEERR

RESETSFCDISTIMEDISTRANSDISACTSTEPUNSTEPDEPRESETERRDISRMOTE

SFCCNTRL

BOOLBOOLBOOLBOOLBOOLBOOLBOOLBOOL

BOOLBOOLBOOLBOOLBOOLBOOLBOOL

SFC-SECTION

Concept V2.5

Animation Control with SFCCNTRL

The function block offers the same control actions that are availablethrough the menu commands of the online menu and the animation panel.

The execution of a SFC section can be influenced process dependent.

SFCCNTRL has to be placed into a section that will be processed PRIOR to the SFC section that is to be controlled.

The assignment of SFCCNTRL to an SFC section is performed through the name of the instance.Instance name = name of SFC_Section

Concept V2.5

Parameter Description (Inputs)

Parameter Data Type Meaning

RESETSFC BOOL 01: Reset sequence; 1 0: Standardized start of sequence (set initial step)

DISTIME BOOL 1: Disconnect watchdog

DISTRANS BOOL 1: Disconnect evaluation of transitions

DISACT BOOL 1: Disconnect processing of actions andreset all actions of the sequence

STEPUN BOOL 01: Activate next step independent oftransition

STEPDEP BOOL 01: Activate next step when transitioncondition satisfied

Concept V2.5

Parameter Description (Inputs)

Parameter Data Type Meaning

RESETERR BOOL 01: Disconnect display of timing errorsin the on-line image.

DISRMOTE BOOL 1: Inhibits the control of SFC with the on-line Animation Panel. The SFC

Sectionmay still be controlled with the

SFCCNTRLFunction Block

Concept V2.5

Parameter Description (Outputs)

Parameter Data Type Meaning

RESET BOOL 1: Sequence was reset

TIME BOOL 1: Watchdog was disconnected

TRANS BOOL 1: Evaluations of transitions disconnected

ACT BOOL 1: Processing of actions has been disconnected and all actions have

been reset

MODECHG BOOL 1: Operating mode has been changed

STATECHG BOOL 1: State of the sequence has been changed

TIMEERR BOOL 1: Watchdog error has occurred

Concept V2.5