FB_MeteringScrew

Implements the metering screw of an injection unit. A combination with an FB_Injector completes the components of an injection unit.

Internal functions:

Synchronization with a back pressure control for metering processes
Automated assurance of screw movability

Syntax:

FUNCTION_BLOCK FB_MeteringScrew EXTENDS FB_CamAxis

Properties

Name	Type	Access	Initial value	Description
Name	STRING	Get, Set	<SourceName>	Specifies the name of the class instance.
FB_MeteringScrew
BackPressureRequired	BOOL	Get, Set	TRUE	If TRUE, the class for metering waits for the activation of the back pressure control of the connected injector.
IsMetering	BOOL	Get	FALSE	A metering process is active.
MeteringDone	BOOL	Get	FALSE	The metering process has reached the target volume and has ended.
MovabililtyCheckRequired	BOOL	Get, Set	FALSE	If TRUE, a movability check is started when the machine is switched on for the first time after it is started.
WaitForInjector	BOOL	Get	FALSE	TRUE when waiting for the back pressure control of the injector.
FB_CamAxis
EnableEnvelopeCurveAlarms	BOOL	Get, Set	FALSE	Enables monitoring of the actual curve in relation to the configured envelope.
FB_Axis
Axis	I_AxisBase	Get	NULL	Interface to the assigned TF8560 axis.
Referencing	I_Referencing	Get	<Local>	Functions for referencing the axis.
FB_Motion
Motion	I_MotionBase	Get	NULL	Interface to the assigned TF8560 motion object.
ErrorAlarmTL	TcEventSeverity	Get, Set	Error (3)	Severity of the alarm that the axis triggers in the error state.
Specific	I_MotionSpecific	Get	-	Technology-specific functions/values
FB_BaseMd
MachineData	I_MdBaseContainer	Get	-	Interface for machine data handling.
FB_Base
BaseState	E_BaseState	Get	eNotHandled	Initialization state of the class instance.
Error	BOOL	Get	FALSE	Class is in an error state.
ResultMessage	I_AppMessage	Get	-	Access to the class-internal EventLogger.
[`PROTECTED`] _Name	STRING	Get	<SourceName>	`.Name` without leading 'fb'.

Methods

Name	Description
Reset()	Resets the error state of the class.
FB_MeteringScrew
Metering(`bCommand`)	Starts/stops the metering process
SetInjector(`iInjector`)	Assigns an injector to the metering screw.
FB_CamAxis
SetCurve(`iCurve`)	Assign the curve to be used
FB_Axis
SetPosition(`bCommand`)	Setting the axis position with the `FB_AxisHmi.Setposition.`
FB_Motion
CheckAxisState()	Checks the current state of the axis.
FeedEnable(`bFeedEnableP, bFeedEnableN`)	Enable of a direction of movement.
JogNegative(`bCommand`)	Starts/stops a jog movement in negative direction.
JogPositive(`bCommand`)	Starts/stops a jog movement in positive direction.
Power(`bCommand`)	Switching on the drive control.
SetMotionRef(`iMotion`)	Assignment method for the TF8560 motion object.
FB_BaseMd
[`PROTECTED`] AddMdComp()	Adds a component of type I_MdComponent to the machine data container.
FB_Base
GetHMI()	Returns the assigned HMI object. Notice The method is not implemented in the `FB_Base` class. If the method is not overwritten by inheritance, a pseudo variable is always returned.
SetHMI(`ipBase`)	General assignment method for an `FB_BaseHmi` extending class as a local HMI. Notice The method is not implemented in the `FB_Base` class. If the method is not overridden by inheritance, it always fails.
[`PROTECTED`] _IsMyself(`iCmp`)	Identifies whether the transferred object corresponds to its own instance.
[`PROTECTED`] _QueryNamespace()	Extracts the first part of the instance path as an object namespace.
[`PROTECTED`] _QueryObjectName()	Extracts the last part of the instance path as the object name.

Procedure controlling methods (FB_AdaptableSequence)

Name	Description
States()	Procedure for carrying out the metering process and the movability check.

Possible events

ID	Description	Alarm/Message
11	Object error state	Alarm
21	Command rejected	Alarm
715x	Error in the movability check	Message
716x	Error during the metering process	Message
301x	Envelope limit exceeded	Alarm
10	Axis Errors	Alarm
20	Axis command rejected	Alarm

Machine data

Component	Description	Index range	Number of instances
FB_MdFileInfo	File information	0x0000 Fxxx	1
FB_MdAxis	Applicative axis parameters	0x0000 1xxx	1
FB_MdNc	NC specific parameters, only if `Specific.Nc.IsNc = TRUE`	0x0000 22xx	1 (0)
FB_MdTrafo	Transformation-specific parameters, only if `Specific.Trafo.IsTrafo = TRUE`	0x0000 23xx	1 (0)
FB_MdHoming	Parameters for homing the axis	0x0000 3xxx	1

Interfaces

Type	Description
I_Base	Standard interface on FB_Base.
I_MeteringScrew	Standard interface on FB_MeteringScrew.
I_CamAxis	Standard interface on FB_CamAxis.
I_Axis	Standard interface on FB_Axis.
I_Motion	Standard interface on FB_Motion
I_TwoTaskInterface	Runtime interface for two PLC tasks.
I_BaseMd	Standard interface on FB_BaseMd.
I_BaseDev	Covers all methods and properties of the base class.
I_Comparable	Enables comparisons via `_IsMyself()` or F_IsSameInstance().

Requirements

Development environment	Target platform	PLC libraries to include
TwinCAT 4026 >= v3.1.4026.19 TwinCAT 4024 >= v3.1.4024.71	PC or CX (x64, x86)	Tc3_PlasticBaseApplication (>= v12.14.0.0)

Further Information

States()