Pseudo-Motors control¶

This is the basic Python class using a set of EPICS motors and formulas to create a Pseudo Motor.

Using EPICS Pseudo-Motors control module¶

Usage of Python class for Pseudo-Motors control.

class py4syn.epics.PseudoMotorClass.PseudoMotor(mnemonic, description, backwardFormula, forwardFormulasDict)[source]¶

Class to control Pseudo-Motor (virtual Motor).

Examples

>>> from py4syn.epics.PseudoMotorClass import PseudoMotor
>>>    
>>> def createPseudoMotor(mnemonic="", description="", backwardFormula="", forwardFormulasDict= []):
...    
...    new_pseudo_motor = ''
...    
...    try:
...        new_motor = PseudoMotor("motorName", "pseudo-motor to help controlling experiment", "", [])
...            print "Motor " + pvName + " created with success!"
...    except Exception,e:
...        print "Error: ",e
...    
...    return new_pseudo_motor

Pseudo Motor class Constructor

Parameters:	mnemonic : string Motor mnemonic description : string Motor Description backwardFormula : string Mathematical Formula used to calculate the Pseudo motor position based on other motors forwardFormulasDict : dictionary Dictionary containing mathematical relations to move each of the motors involved in the pseudo motor movement

canPerformMovement(target)[source]¶

Check if a movement to a given position is possible using the limit values and backlash distance

Returns:	`boolean` .. note:: True – Motor CAN perform the desired movement; False – Motor CANNOT perform the desired movement.

getBacklashDistanceValue()[source]¶

Read the motor backlash distance based on the BDST (Backlash Distance, EGU) field of virtual Motor

Returns:	`double`

getDescription()[source]¶

Read the motor description based on the DESC (Description) field of virtual Motor

Returns:	`string`

getDialHighLimitValue()[source]¶

Read the motor dial high limit based on the DHLM (Dial High Limit) field of virtual Motor

Returns:	`double`

getDialLowLimitValue()[source]¶

Read the motor dial low limit based on the DLLM (Dial Low Limit) field of virtual Motor

Returns:	`double`

getDialPosition()[source]¶

Read the motor target DIAL position based on the DVAL (Dial Desired Value) field of virtual Motor

Returns:	`double`

getDialRealPosition()[source]¶

Read the motor DIAL real position based on the DRBV (Dial Readback Value) field of virtual Motor

Returns:	`double`

getDirection()[source]¶

Read the Pseudo motor direction

Returns:	`integer` .. note:: Positive direction; Negative direction.

getEGU()[source]¶

Read the motor engineering unit based on the EGU (Engineering Units) field of the virtual Motor

Returns:	`string`

getFreezeOffset()[source]¶

Read the motor freeze offset based on the FOF (Freeze Offset) field of virtual Motor

Returns:	`integer`

getHighLimitValue()[source]¶

Read the motor high limit based on the HLM (User High Limit) field of virtual Motor

Returns:	`double`

getLVIO()[source]¶

Read the motor limit violation LVIO (Limit Violation) field of the virtual Motor

Returns:	`short`

getLimitValue(high)[source]¶

Auxiliary method called by getHighLimitValue() and getLowLimitValue() to get the high and low limit values of a pseudo motor. The limits are calculated based on a maximization or minimization, depending on the high parameter, of the pseudo motor equation, considering the bounds of the real motors.

See getHighLimitValue(), getLowLimitValue()

Parameters:	high : bool True if the high limit value is requested, false if the low limit is requested.
Returns:	`double`

getLowLimitValue()[source]¶

Read the motor low limit based on the LLM (User Low Limit) field of virtual Motor

Returns:	`double`

getOffset()[source]¶

Read the motor offset based on the OFF (User Offset, EGU) field of virtual Motor

Returns:	`string`

getPosition()[source]¶

Read the motor target position based on the VAL (User Desired Value) field of virtual Motor

Returns:	`double`

getRawPosition()[source]¶

Read the motor RAW position based on the RVAL (Raw Desired Value) field of Motor Record

Returns:	`double`

getRawRealPosition()[source]¶

Read the motor RAW real position based on the RRBV (Raw Readback Value) field of Motor Record

Returns:	`double`

getRealPosition()[source]¶

Read the motor real position based on the RBV (User Readback Value) field of virtual Motor

Returns:	`double`

getValue()[source]¶

Get the current position of the motor. See py4syn.epics.IScannable

Returns:	`double` Read the current value (virtual Motor Real Position)

getVariableOffset()[source]¶

Read the motor variable offset based on the VOF (Variable Offset) field of virtual Motor

Returns:	`integer`

isAtHighLimitSwitch()[source]¶

Check if the high limit switch of any of the motors is activated

Returns:	`int` .. note:: 1 – At least one Motor is at High Limit; 0 – NO one of the Motors is at High Limit.

isAtLowLimitSwitch()[source]¶

Check if the low limit switch of any of the motors is activated

Returns:	`int` .. note:: 1 – At least one Motor is at Low Limit; 0 – NO one of the Motors is at Low Limit.

isMoving()[source]¶

Check if any of the motors are moving

Returns:	`boolean` .. note:: True – At least one Motor is being moved; False – NO one of the Motors is being moved.

setAbsolutePosition(pos, waitComplete=False)[source]¶

Move the motor to an absolute position received by an input parameter

Parameters:	pos : double The desired position to set waitComplete : boolean (default is False) Note If True, the function will wait until the movement finish to return, otherwise don’t.

setAcceleration(accl)[source]¶

Set the motor acceleration time based on the ACCL (Seconds to Velocity) field from virtual Motor

Parameters:	accl : double The desired acceleration to set

setDialHighLimitValue(val)[source]¶

Set the motor dial high limit based on the DHLM (Dial High Limit) field of virtual Motor

Parameters:	val : double The desired value to set

setDialLowLimitValue(val)[source]¶

Set the motor dial low limit based on the DLLM (Dial Low Limit) field of virtual Motor

Parameters:	val : double The desired value to set

setDialPosition(pos, waitComplete=False)[source]¶

Set the motor target DIAL position based on the DVAL (Dial Desired Value) field of virtual Motor

Parameters:	pos : double The desired position to set waitComplete : boolean (default is False) Note If True, the function will wait until the movement finish to return, otherwise don’t.

setEGU(unit)[source]¶

Set the motor engineering unit to the EGU (Engineering Units) field of virtual Motor

Parameters:	unit : string The desired engineering unit. Note Example: “mm.”, “deg.”

setFreezeOffset(val)[source]¶

Set the motor freeze offset based on the FOF (Freeze Offset) field of virtual Motor

Parameters:	val : integer The desired value to set

setHighLimitValue(val)[source]¶

Set the motor high limit based on the HLM (User High Limit) field of virtual Motor

Parameters:	val : double The desired value to set

setLowLimitValue(val)[source]¶

Set the motor low limit based on the LLM (User Low Limit) field of virtual Motor

Parameters:	val : double The desired value to set

setOffset(val)[source]¶

Set the motor offset based on the OFF (User Offset, EGU) field of virtual Motor

Parameters:	val : double The desired value to set

setRelativePosition(pos, waitComplete=False)[source]¶

Move the motor a distance, received by an input parameter, to a position relative to that current one

Parameters:	pos : double The desired distance to move based on current position waitComplete : boolean (default is False)

setSETMode()[source]¶: Put the motor in SET mode

Note

Motor will NOT move until it is in in USE mode

setUSEMode()[source]¶: Put the motor in USE mode

setUpdateRequest(val)[source]¶

Set the motor update request flag based on the STUP (Status Update Request) field from virtual Motor

Parameters:	val : integer The desired value to set for the flag

setValue(v)[source]¶

Set the desired motor position. See py4syn.epics.IScannable

Parameters:	v : double The desired value (Absolute Position) to set

setVariableOffset(val)[source]¶

Set the motor variable offset based on the VOF (Variable Offset) field of virtual Motor

Parameters:	val : integer The desired value to set

setVelocity(velo)[source]¶

Set the motor velocity up based on the VELO (Velocity, EGU/s) field from virtual Motor

Parameters:	velo : double The desired velocity to set

stop()[source]¶: Stop the motor

validateLimits()[source]¶: Verify if motor is in a valid position. In the case it has been reached the HIGH or LOW limit switch, an exception will be raised.

wait()[source]¶: Wait until the motor movement finishes

class py4syn.epics.PseudoMotorClass.motorPosition[source]¶

Class to globally control positioning of virtual Motor

__getitem__(m)[source]¶

Get current value of the virtual Motor positionin

Parameters:	m : dictionary Represents the device, virtual Motor, in the mtrDB global array of devices
Returns:	`double` Read the current value (virtual Motor Real Position)

__weakref__¶: list of weak references to the object (if defined)

class py4syn.epics.PseudoMotorClass.motorPositionDial[source]¶

Class to globally control positioning of virtual Motor using Dial fields

__getitem__(m)[source]¶

Get current value of the virtual Motor positioning using Dial field

Parameters:	m : dictionary Represents the device, virtual Motor, in the mtrDB global array of devices
Returns:	`double` Read the current Positioning value of virtual Motor (Real) using Dial field

__weakref__¶: list of weak references to the object (if defined)

class py4syn.epics.PseudoMotorClass.motorTarget[source]¶

Class to globally control virtual Motor targets

Constructor

Parameters:	None

__getitem__(m)[source]¶

Get current value of the virtual Motor positioning

Parameters:	m : dictionary Represents the device target, virtual Motor, in the mtrDB global array of devices
Returns:	`double` or `dictionary` item Read the current Positioning value of virtual Motor (Real) Note If m parameter is received and it is in the targets list, then its correspondent target is returned (as a dictionary item), otherwise, real position of virtual Motor is returned (as a double value)

__init__()[source]¶

Constructor

Parameters:	None

__setitem__(m, pos)[source]¶

Set a position value to the virtual Motor target received as input parameter

Parameters:	m : dictionary Represents the target device, virtual Motor, in the mtrDB global array of devices pos : double The desired position to set

__weakref__¶: list of weak references to the object (if defined)

keys()[source]¶

Get keys (indexes) of all virtual Motor targets

Returns:	`integer array` Read the keys (indexes) from all targets

class py4syn.epics.PseudoMotorClass.motorTargetDial[source]¶

Class to globally control virtual Motor target using Dial fields

Constructor

Parameters:	None

__getitem__(m)[source]¶

Get current value of the virtual Motor positioning using Dial field

Parameters:	m : dictionary Represents the device target, virtual Motor, in the mtrDB global array of devices
Returns:	`double` or `dictionary` item Read the current Positioning value of virtual Motor (Real) Note If m parameter is received and it is in the targets list, then its correspondent target is returned (as a dictionary item), otherwise, real position of virtual Motor, using the Dial field, is returned (as a double value)

__init__()[source]¶

Constructor

Parameters:	None

__setitem__(m, pos)[source]¶

Set a position value to the virtual Motor target received as input parameter

Parameters:	m : dictionary Represents the target device, virtual Motor, in the mtrDB global array of devices pos : double The desired position to set

__weakref__¶: list of weak references to the object (if defined)

keys()[source]¶

Get keys (indexes) of all virtual Motor targets

Returns:	`integer array` Read the keys (indexes) from all targets