Table of Contents

AxisPlcOpenMc

Namespace
ZEquipment
Extends
Inherited Properties
Inherited Methods
Implements
FUNCTION_BLOCK AxisPlcOpenMc EXTENDS ZEquipment.Axis IMPLEMENTS ZEquipment.IAxisHoming, ZEquipment.IAxisMovePosition, ZEquipment.IAxisMoveVelocity, ZEquipment.IAxisFeedbackPosition, ZEquipment.IAxisFeedbackVelocity, ZEquipment.IAxisFeedbackCurrent, ZEquipment.IAxisHalt, ZEquipment.IAxisVelocityFeedrate, ZEquipment.IAxisBase, ZCore.IObject, ZCore.IBootable, ZCore.IError (
 [output] Diagnostics : ZCore.DiagnosticMessage)

This function blocks implements the general axis interfaces by utilizing motion controllers that are conform to the PLCopen standard. This is the goto axes implementation of the Zeugwerk Framework if you want to control your axes via NC Motion (TwinCAT) or Softmotion (Codesys).

Internally, AxisPlcOpenMc uses MC function blocks (standardized by the PLCopen) to implement the Zeugwerk Framework's axis interfaces (i.e. IAxisBase, IAxisMovePosition, ...).

However, this implementation is not only a simple wrapper of MC function blocks, it also simplifies the usage of said function blocks. Any method that is suffixed with Async will automatically take care of fulfilling its preconditions. For instance, a call to MoveAbsoluteAsync will automatically execute an error reset if neccessary and will power on the axis.

  • Unlock the drive if it has been locked before (AxisPlcOpenMc only)
  • Reset any drive errors if there are still errors, which have not been acknowledged yet
  • Write parameters to the drive that have been requested to read or write by using the Parameter property of each specialised axis
  • Enable the drive if it is not enabled yet

Besides implementing the axis interfaces of the Zeugwerk Framework, this function block offers some methods, which are specific to PLCopen (e.g. TwinCAT NC)

  • Use AxisRef to get hold of the AXIS_REF object. This is mainly needed for multiaxes applications (i.e. gantry), since AxisPlcOpenMc is meant for convienent single axis usage only.
  • (Twincat NC only) Use VelocityFeedrate to overwrite all velocities in percent.

Outputs

Diagnostics DiagnosticMessage

Constructor

FB_init 

METHOD FB_init (
 [input] bInitRetains : BOOL,
 [input] bInCopyCode : BOOL,
 [input] parent : ZCore.IManagedObject) : BOOL

Inputs

bInitRetains BOOL

if TRUE, the retain variables are initialized (warm start / cold start)

bInCopyCode BOOL

if TRUE, the instance afterwards gets moved into the copy code (online change)

parent IManagedObject

Returns

BOOL

Properties

ActualCurrent 

PROPERTY ActualCurrent : LREAL

Property Value

LREAL

ActualFollowingError 

PROPERTY ActualFollowingError : LREAL

Property Value

LREAL

ActualPosition 

PROPERTY ActualPosition : LREAL

Returns the actual position of the axis, which is usually related to a position encoder or resolver. The value returned is given in drive positional-unit, which is usually millimeters or degrees, respectively.

Property Value

LREAL

ActualSafetyState 

PROPERTY ActualSafetyState : AxisSafetyStateFlags

This property can be used to test if a given safety feature of a drive is currently activated or not. Note that the property returns a "Flags" enumeration, which means that several bits of the returned value can be on at the same time.

Note

Retrieving the safety state of a drive is manufacturer specific.

  • Some drives may not support some of the features that are depicted in the returned value (some bits may always be 0).
  • Generic axes implementation (i.e. AxisPlcOpenMc) of the Zeugwerk Framework usually do not return the correct safety state of the drive. In doubt refer to the documentation of your specific implementation.
Warning

Since this axis implementation is generic it can not correctly return the safety state of the drive. The return value will always be 0 (no bit of the returned type is set)

Property Value

AxisSafetyStateFlags

ActualVelocity 

PROPERTY ActualVelocity : LREAL

Property Value

LREAL

Parameter 

PROPERTY Parameter : IAxisPlcOpenMcParameter

This property returns an interface to the central parameterization entry point of an PlcOpen Mc Axis. Usually parameters are split in

  • Booting parameters
  • Drive parameters: homing parameters, positioning type and modulo settings can be accessed here
  • Plc parameters: maximum speed and conversion parameters
  • Simulation parameters: setting an initial (simulated) position, jerk and acceleration of the simulated trajectory

It is also possible to return the ParameterChannel interface to be able to access every parameter needed of an Axis PlcOpen Mc instance

Property Value

IAxisPlcOpenMcParameter

Referenced 

PROPERTY Referenced : BOOL

This property can be used to test if an axis is referenced correctly. For axes that use an incremental encoder, this means that a homing procedure has been already been executed correctly. For axes that use an absolute encoder, this usually means that the encoder has been initialized correctly.

Read the documentation of your axes implementation (i.e. AxisPlcOpenMc) for more specifics.

Property Value

BOOL

Simulation 

PROPERTY Simulation : BOOL

This property can be used to enable or disable simulation mode of this axis. Whenever the simulation flag is changed, the drive will automatically (re-)initialize by performing its booting sequence. Hence, it is possible to switch to simulation and back while the PLC is running. The simulated axis instance utilizes AxisSimulatedImpl, which in turn uses the Online-Trajectory-Generator to generate motion profiles.

Warning

Some PLCopen conform motion controllers (NC Motion) come with a built-in simulation mode on their side. This property will have no impact to the simulation mode of the motion controller. Thus, when setting up the motion controller, one can use a simulated (by the motion controller) axis instance, even if on=FALSE.

Property Value

BOOL

State 

PROPERTY State : ZCore.ObjectState

Returns the object state of the axis object. This exposes if an object is still in its booting phase, had an error, or is busy executing an async action.

Property Value

ObjectState

VelocityFeedrate 

PROPERTY VelocityFeedrate : LREAL

Property Value

LREAL

Methods

AxisRef 

METHOD AxisRef () : REFERENCE TO ZPlatform.PlcOpenAxisRef

Returns

REFERENCE TO PlcOpenAxisRef

HaltAsync 

METHOD HaltAsync (
 [input] startToken : ZCore.IStartToken)

Inputs

startToken IStartToken

pass an StartToken instance here to check if the call was successfully executed

HomingAsync 

METHOD HomingAsync (
 [input] startToken : ZCore.IStartToken)

Inputs

startToken IStartToken

(optional) object to check if the method was executed successfully - may be 0

IsAtPosition 

METHOD IsAtPosition (
 [input] pos : LREAL,
 [input] window : LREAL) : BOOL

Inputs

pos LREAL
window LREAL

Returns

BOOL

MoveAbsoluteAsync 

METHOD MoveAbsoluteAsync (
 [input] startToken : ZCore.IStartToken,
 [input] position : LREAL,
 [input] speed : LREAL)

Starts to move the axes to a specific position with a given velocity. The method utilizes the drive's profile generator, which may offer to adjust acceleration, deceleration and jerk as PDOs or SDOs as well. The latter parameters are usually vendor specific and thus are not part of the interface. Use the Parameter property of each specialised axis to adjust said values before calling this method. Calling this method will beforehand automatically trigger the following sequences

  • Unlock the drive if it has been locked before (AxisPlcOpenMc only)
  • Reset any drive errors if there are still errors, which have not been acknowledged yet
  • Write parameters to the drive that have been requested to read or write by using the Parameter property of each specialised axis
  • Enable the drive if it is not enabled yet

Executing this method while the drive is still Busy with another Async command will cause this method to fail. This can be checked by submitting an StartToken as a startToken. Simply pass such an object and Assert it or check for startToken.Error after calling this method.

If a MoveAbsoluteAsync or MoveRelativeAsync command is currently being executed, calling this method can be used to overwrite the current move command. This is an exeception to the rule that this method should not be called while the axis is busy.

Inputs

startToken IStartToken

pass an StartToken instance here to check if the call was successfully executed

position LREAL

Position in drive position units, usually millimeter or degree

speed LREAL

Speed in drive speed units, usually millimeter-per-second, or degree-per-second

MoveRelativeAsync 

METHOD MoveRelativeAsync (
 [input] startToken : ZCore.IStartToken,
 [input] distance : LREAL,
 [input] speed : LREAL)

Starts to move the axes to a specific distance from its current position with a given velocity. The method utilizes the drive's profile generator, which may offer to adjust acceleration, deceleration and jerk as PDOs or SDOs as well. The latter parameters are usually vendor specific and thus are not part of the interface. Use the Parameter property of each specialised axis to adjust said values before calling this method. Calling this method will beforehand automatically trigger the following sequences

  • Unlock the drive if it has been locked before (AxisPlcOpenMc only)
  • Reset any drive errors if there are still errors, which have not been acknowledged yet
  • Write parameters to the drive that have been requested to read or write by using the Parameter property of each specialised axis
  • Enable the drive if it is not enabled yet

Executing this method while the drive is still Busy with another Async command will cause this method to fail. This can be checked by submitting an StartToken as a startToken. Simply pass such an object and Assert it or check for startToken.Error after calling this method.

If a MoveAbsoluteAsync or MoveRelativeAsync command is currently being executed, calling this method can be used to overwrite the current move command. This is an exeception to the rule that this method should not be called while the axis is busy.

Inputs

startToken IStartToken

pass an StartToken instance here to check if the call was successfully executed

distance LREAL

Position in drive position units, usually millimeter or degree

speed LREAL

Speed in drive spped units, usually millimeter-per-second, or degree-per-second

MoveVelocityAsync 

METHOD MoveVelocityAsync (
 [input] startToken : ZCore.IStartToken,
 [input] velocity : LREAL)

If a MoveVelocityAsync command is currently being executed, calling this method can be used to overwrite the current move command. This is an exeception to the rule that this method should not be called while the axis is busy.

Inputs

startToken IStartToken

pass an StartToken instance here to check if the call was successfully executed

velocity LREAL

velocity in drive velocity units, usually millimeter-per-second, or degree-per-second; for variable frequency drives rotations/minute are common

RebootAsync 

METHOD RebootAsync (
 [input] startToken : ZCore.IStartToken)

Reboot of the axis, which means that the internal state is switched back to Booting. In practice, this switches the axis' fieldbus back to PREOP, writes all parameters to the drive and then switches back to OP. Internally this is achieved by parking the axis and then unparking it.

Inputs

startToken IStartToken

pass an StartToken instance here to check if the call was successfully executed

SetLogger 

METHOD SetLogger (
 [input] logger : ZCore.ILogger)

Use this method together with SetName to enable logging for this axis. Various methods of this implementation write log messages into the passed logger interface.

Note

Sometimes it is beneficial to disable logging by passing 0 to this method (e.g. for inputs or outputs which are switch very often).

Inputs

logger ILogger

SetName 

METHOD SetName (
 [input] name : ZCore.ZString)

Sets the name of this object as it will show up in any log messages that is created by this object. The name set with this method should be relatable to the name of the input in the electrical plan of your automation project to identify the corresponding input properly.

Inputs

name ZString

SetSimulation 

METHOD SetSimulation (
 [input] on : BOOL)

Inputs

on BOOL