vcPythonTransportController

This is a transport controller behavior that delegates the concrete implementation to user-made Python script(s), which allows creating specialized and custom transport controllers. The behaviour provides events and methods required to handle transport and work tasks. Python transport controller behaviours can be added to static components.

The script implementation should subscribe to the OnBeginTransport and OnBeginWorkEx events. When these events are triggered, the script is expected to create tasks to some internal queue and process them asynchronously. Transport controllers must accept and handle all “assigned” transport and work tasks to completion, there is no task rejection or cancellation mechanism. If and how a transport controller uses separate resources for completing the tasks is entirely up to the specific implementation to decide.

A transport task is considered done when the product instance is placed into the target component container. The target container and position should be queried from the target transport node using the method vcTransportNode.getTransportTarget(vcProduct product).

Work tasks need to be completed by calling the workDone method using the RequestId that was received in the OnBeginWorkEx event.

Transport controllers get an event when the controller is assigned as an implementer of a transport link, and similarly when a link is assigned some other controller. These events (OnLinkAssociated and OnLinkDisassociated) allow the controller to create any custom properties into all transport links it implements.

Inherits: vcTransportController, vcBehaviour

Type constant: VC_PYTHONTRANSPORTCONTROLLER

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Properties
Methods
Events
Examples

Properties

Name	Type	Access	Description
Icon	String	RW	The icon file used to represent this transport controller in UI. Defines either filesystem path to the SVG image file or an SVG path data. Both relative and absolute paths with/without .svg extension are allowed. Relative paths are relative to the Icons or Icons. Additional folder under VC installation folder. Example: “UPM/pDroneTransportController”
IconColor	String	RW	Fill color applied to the of the Icon in ARGB, RGB or unqualified-color-name format. (e.g. #FFFF0000 or #FF0000 or Red)
IsSystem	Boolean	R	Always returns False.

Methods

Name	Return Type	Parameters	Description
workDone	None	Integer workId	Notifies the Work statement that work has been done so the process can continue executing.

Events

Name

Parameters

Description

LinkAssociated

vcTransportLink link

(Deprecated) Use OnLinkAssociated.

LinkDisassociated

vcTransportLink link

(Deprecated) Use OnLinkDisassociated.

OnBeginTransport

List of 2-tuple (vcTransportLink link, vcProduct product) products

Triggered when the transport controller is asked to transport one or more products. Each product should be transported to the Destination node of the respective transport link.

OnBeginWork

Integer workId,

vcProperty processTime,

vcMatrix resourcePosition,

vcMatrix workPosition

(DEPRECATED) Use the extended version OnBeginWorkEx instead.

Triggered when a Work statement gets executed. workDone with correct workId must be called at some point for Work statement to continue execution. If a handler is not registered, Work statement might wait indefinitely.

workId is a unique (within this transport controller) identifier of this work assignment.

processTime is a property that defines how long the work itself should take in seconds.

resourcePosition defines a position hint in world coordinates where the working resource is expected to be while doing the work.

workPosition defines a position hint in world coordinates where the actual work is expected to happen.

OnBeginWorkEx

vcDataContainer arguments

Triggered when a Work statement gets executed. workDone with correct request id must be called at some point for Work statement to continue execution. If a handler is not registered, Work statement might wait indefinitely.

The arguments object has the following attributes:

Name	Type	Access	Description
RequestId	Integer	R	Unique (within this transport controller) identifier of this work assignment.
RequestingProcess	vcProcessRoutine	R	The process implementation that requested this work.
ProcessTime	Real	R	A value that defines how long the work itself should take in seconds.
ResourcePositionMatrix	vcMatrix	R	Position hint in world coordinates where the working resource is expected to be while doing the work.
WorkPositionMatrix	vcMatrix	R	Position hint in world coordinates where the actual work is expected to happen.

OnLinkAssociated

vcTransportLink link

Raised when a transport link is associated with this controller. If a handler is not registered, the default internal implementation is called.

OnLinkDisassociated

vcTransportLink link

Raised when a transport link is disassociated from this controller. If a handler is not registered, the default internal implementation is called.

Examples

Example. Defining Custom-Made Transport Controller

from vcScript import *

# Minimal transport controller script.
# Product simply jumps to the target container and position
# transportation time is defined in transport link property MyTime

def transport_request_event(request_list):
  # Event executed when transportation is requested from this controller
  for transport_link, product in request_list:
    queue.append([transport_link, product])
  trigger.signal(True) # dummy boolean signal connected to the script to trigger condition in onrun

def OnStart():
  global queue
  queue = []


def OnRun():
  while True:
    condition(lambda: queue)
    transport_link, product = queue.pop(0)
    destination = transport_link.Destination # additional info can be accessed via trasportlink
    target_container = destination.ComponentContainer
    target_matrix = destination.getTransportTarget(product).ProductPosition
    part = product.Component
    delay(transport_link.MyTime)
    sim.World.attach(part) # attach to world as matrix is given in world coords
    part.PositionMatrix = target_matrix
    target_container.grab(part)
def link_associated_event(transport_link):
  prop = transport_link.createProperty(VC_REAL, 'MyTime')
def link_disassociated_event(transport_link):
  prop = transport_link.getProperty('MyTime')
  if prop:
    transport_link.deleteProperty(prop)

comp = getComponent()
sim = getSimulation()
trigger = comp.findBehaviour('TriggerSignal')
transport_controller = comp.findBehaviour('PythonTransportController')
transport_controller.OnBeginTransport = transport_request_event
transport_controller.LinkAssociated = link_associated_event
transport_controller.LinkDisassociated = link_disassociated_event

#creating product properties that not supported in UI
# 1. create a distribution property to a product type
# 2. during simulation, take a sample of the distribution
# 3. use that sample value to a Real type property in the Product instance.