If you want to create a plugin in order to access piezo- or motor-stages, multi-axes-machines,... it is intended to derive your plugin class from ito::AddInActuator.
The actuator interface has been developed with the following base ideas:
In order to program the actuator plugin, follow these steps:
Create the header and source file for your plugin “MyActuatorPlugin”.
Create the interface (or factory) class “MyActuatorPluginInterface”. For details about how to create such an interface class, see Plugin interface class.
Create the plugin class “MyActuatorPlugin” with respect to the exemplary implementation, given in the next section.
- Consider which internal parameters, that can be read and/or written by the user, your plugin has. Add these parameters in the constructor of your plugin to the m_params-vector.
- Implement the init-method that gets the initial parameters, defined in the interface class.
- Implement the methods getParam and setParam, which are the getter- and setter-methods for the internal parameters.
- Implement the motor-specific methods, including waitForDone
A sample header file of the actuator’s plugin class is illustrated in the following code snippet:
1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 25 26 27 28 29 30 31 32 33 34 35 36 37 38 39 40 41 42 43 44 45 46 47 48 49 50 51 52 53 54 55 56 57 58 59 60 61 62 63 | #define ITOM_IMPORT_API
#define ITOM_IMPORT_PLOTAPI
#include "../../common/addInInterface.h"
#include "dialogMyMotor.h"
#include "dockWidgetMyMotor.h"
class MyMotor : public ito::AddInActuator
{
Q_OBJECT
protected:
~MyMotor() {}; /*! < Destructor*/
MyMotor();/*! < Constructor*/
ito::RetVal waitForDone(int timeoutMS = -1, QVector<int> axis = QVector<int>() /*if empty -> all axis*/, int flags = 0 /*for your use*/);
public:
friend class MyMotorInterface;
const ito::RetVal showConfDialog(void); /*!< Opens the modal configuration dialog (called from main thread) */
int hasConfDialog(void) { return 1; }; /*!< indicates that this plugin has got a configuration dialog */
public slots:
//! get/set parameters
ito::RetVal getParam(QSharedPointer<ito::Param> val, ItomSharedSemaphore *waitCond = NULL);
ito::RetVal setParam(QSharedPointer<ito::Param> val, ItomSharedSemaphore *waitCond = NULL);
//! init/close method
ito::RetVal init(QVector<ito::Param> *paramsMand, QVector<ito::Param> *paramsOpt, ItomSharedSemaphore *waitCond = NULL);
ito::RetVal close(ItomSharedSemaphore *waitCond);
//! calibration for single or multiple axis
ito::RetVal calib(const int axis, ItomSharedSemaphore *waitCond = NULL);
ito::RetVal calib(const QVector<int> axis, ItomSharedSemaphore *waitCond = NULL);
//! current axis position is new zero-position
ito::RetVal setOrigin(const int axis, ItomSharedSemaphore *waitCond = NULL);
ito::RetVal setOrigin(const QVector<int> axis, ItomSharedSemaphore *waitCond = NULL);
//! Reads out status request answer and gives back ito::retOk or ito::retError
ito::RetVal getStatus(QSharedPointer<QVector<int> > status, ItomSharedSemaphore *waitCond);
//! get current position of single or multiple axis (in mm or degree)
ito::RetVal getPos(const int axis, QSharedPointer<double> pos, ItomSharedSemaphore *waitCond);
ito::RetVal getPos(const QVector<int> axis, QSharedPointer<QVector<double> > pos, ItomSharedSemaphore *waitCond);
//! move one or more axis to certain absolute positions (in mm or degree)
ito::RetVal setPosAbs(const int axis, const double pos, ItomSharedSemaphore *waitCond = NULL);
ito::RetVal setPosAbs(const QVector<int> axis, QVector<double> pos, ItomSharedSemaphore *waitCond = NULL);
//! move one or more axis by certain relative distances (in mm or degree)
ito::RetVal setPosRel(const int axis, const double pos, ItomSharedSemaphore *waitCond = NULL);
ito::RetVal setPosRel(const QVector<int> axis, QVector<double> pos, ItomSharedSemaphore *waitCond = NULL);
//! if this slot is triggered, the current status and position is emitted (e.g. for actualizing a dock widget)
ito::RetVal RequestStatusAndPosition(bool sendActPosition, bool sendTargetPos);
//ito::RetVal requestStatusAndPosition(bool sendCurrentPos, bool sendTargetPos); //!see notes above
private slots:
void dockWidgetVisibilityChanged( bool visible ); /*!< this slot is invoked if the visibility of the dock widget has changed */
};
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The corresponding source file should start with something like this:
1 2 3 4 5 6 | #define ITOM_IMPORT_API
#define ITOM_IMPORT_PLOTAPI
#include "yourHeaderFile.h"
//implement your code here
|
Each actuator has the possibility to signalize the target position, the current position and the current status of each axis. Then its own toolbox or other widgets or slots (general: listeners) can be connected to the corresponding signals in order to be informed about the current activity. The base class ito::AddInActuator provides the necessary structures for this:
1. The vector m_currentPos must be initialized to a length corresponding to the number of axes and contains the current position of every axis using the units stated below. Whenever the actuator registers a change of any current position, the corresponding value should be changed as well. Listeners are finally informed about this change by calling the method
sendStatusUpdate(false)The argument false means that not only a change of the current status happened, but also a change of any current position. This method internally emits the signal actuatorStatusChanged.
The vector m_targetPos must also be initialized to a length corresponding to the number of axes. Whenever a positioning operation starts, set the target value of specific axes to the new target value and call
sendTargetUpdate()that finally emits the signal targetChanged.
The status of every axis is stored in the vector m_currentStatus. Each item in this vector with a length corresponding to the number of axes, contains an OR combination of the enumeration ito::tActuatorStatus. Whenever the status of any axis changes, change its status value, too and use sendStatusUpdate(true/false) in order to also emit the signal actuatorStatusChanged.
The enumeration ito::tActuatorStatus contains the following values that are grouped by specific mask values:
The moving flags contain flags about the current moving status of any axis (bits containing to this group are contained in the mask ito::actMovingMask):
- ito::actuatorUnknown: The current status of this axis is unknown
- ito::actuatorInterrupted: The movement of this axis has been interrupted and no further commands followed
- ito::actuatorMoving: The axis is currently moving (or is supposed to move)
- ito::actuatorAtTarget: The axis reached its target position (this is the default value)
- ito::actuatorTimeout: A timeout occurred during the movement of this axis
The status flags inform about the general status of any axis (bits containing to this group are set in the mask ito::actStatusMask):
- ito::actuatorAvailable: This axis is available (usually set)
- ito::actuatorEnabled: This axis is enabled and can be driven (usually set, but there are drivers that allowing disabling selected axis)
Axes that have got any reference or end switches can signal related status information using the switches flags. All bits belonging to this group are set in the mask ito::actSwitchesMask divided into ito::actEndSwitchMask and ito::actRefSwitchMask):
- ito::actuatorEndSwitch: This bit is set if any (unknown) end switch was reached
- ito::actuatorLeftEndSwitch: This bit is additionally set if the left end switch was reached
- ito::actuatorRightEndSwitch: This bit is additionally set if the right end switch was reached
- ito::actuatorRefSwitch: This bit is set if any (unknown) reference switch was reached
- ito::actuatorLeftRefSwitch: This bit is additionally set if the left reference switch was reached
- ito::actuatorRightRefSwitch: This bit is additionally set if the right reference switch was reached
You can either manually set the necessary bit-combination of moving, status and switch flags for signalling the right status of the axis. There are three methods defined in ito::AddInActuator that simplify this process:
setStatus(int &status, const int newFlags, const int keepMask = 0)
setStatus(const QVector<int> &axis, const int newFlags, const in keepMask = 0)
Use this methods to the set the status of one or multiple axis. The parameter newFlags should contain an or-combination of all flags that should be set. The status flags are then set to this value (hence, old values are overwritten). If you want to keep the current bit values of a certain group, pass the specific mask as argument keepMask. For instance, if you want to the status of the second axis to actuatorMoving without changing the status flags, use the following command:
setStatus(m_currentStatus[1], ito::actuatorMoving, ito::actStatusFlags)
# this command will set all bits of the switches mask to 0!
The equivalent command for multiple axis, requires a vector with axes-indices as first argument. This example does the same for the first and third axis:
QVector<int> axis;
axis << 0 << 2;
setStatus(axis, ito::actuatorMoving, ito::actStatusFlags)
The similar commands replaceStatus
replaceStatus(int &status, const int existingFlag, const int replaceFlag)
replaceStatus(const QVector<int> &axis, const int existingFlag, const int replaceFlag)
can be used to replace one status flag by another one without changing the other bits. If the bit corresponding to the existingFlag is set, it is set to zero and the bit of the replaceFlag is set to 1. In the following example, the flag of the first axis is set from moving to atTarget:
replaceStatus(m_currentStatus[0], ito::actuatorMoving, ito::actuatorAtTarget)
After using one of these functions to set the current status, call sendStatusUpdate to emit the signal actuatorStatusChanged such that connected listeners can for instance visualize the current status.
It is possible to implement an interrupt button in the toolbox of the actuator that becomes active once at least one axis is moving. Once the button is clicked it must directly call the thread-safe function setInterrupt() of the actuator plugin (If the toolbox inherits from ito::AbstractAddInDockWidget call its method setActuatorInterrupt().
In the method waitForDone regularly check if the interrupt flag has been set, using the actuator’s method isInterrupted(). If this method returns true, set the moving state of all moving axes to ito::actuatorInterrupted and return with an appropriate return value, like:
return ito::RetVal(ito::retError, 0, "movement interrupted");
Note
Once isInterrupted() returns true, the internal interrupt flag is reset to false. Therefore consider to call this function to reset the interrupt flag if desired (e.g. at the begin of the next movement).
In order to have a unified behaviour of all actuator plugins, respect the following unit conventions. That means, the plugin should store related parameters using these conventions, such that getParam and setParam returns and obtains values using these units. Internally, it is sometimes necessary to convert these units to the units required by the interface of the real actuator device.
Implement the following mandatory parameters in the map m_params:
name of the plugin
number of connected axes
If 1: asynchronous movement. Methods like setPosAbs or setPosRel only start the movement and immediately return. Hence, the waitCond in waitForDone is directly released before the loop waiting for the end of the movement is executed. If 0: synchronous movement (default). setPosAbs and setPosRel block until the end of the movement, hence, waitCond in waitForDone is only released at the end of the movement. Since waitForDone always is running during the movement, the plugin thread is blocked and no further commands can be executed, even in asynchronous mode.
If desired implement the following optional parameters in the map m_params:
Desired speed for the axes. If double, the speed holds for all axes, else the doubleArray must have the same length than the number of axes, holding the axis specific speed values. Make sure, that it is not possible to set an array of another length in setParam.
Acceleration values (similar to speed)
Deceleration values (similar to speed)