Simulating Power and Free Conveyors

You can define a flow based on Power and Free conveyors and simulate the flow.

This task shows you how to:

Before you begin:
  • Create a Power and Free conveyor in Equipment Design.
  • Define a layout in Plant Layout Design.
See Also
Creating and Modifying a Factory Flow
About Zones
About Activities

Define Points on a Conveyor to Load, Unload, and Route Products

You can define decision zones on a Power and Free conveyor. Decision zones identify points where to load, unload, and route products. You can define one decision zone per conveyor only.

This scenario shows how to define a zone to load products and a zone to unload products.

  1. Open a Power and Free conveyor similar to the one below.

  2. From the Programming section of the action bar, click Add PnF Decision Zone .
  3. Select a pathway on the conveyor.

  4. Select a point on the conveyor where to load products.
    A decision zone appears on the selected point.

  5. Select another point on the conveyor where to unload products.
    A decision zone appears on the selected point.

  6. Press Esc when done.
  7. Select the first decision point and click Edit SLA Resource in the context toolbar that appears.
  8. In the Edit Decision Point dialog box that appears, create a load activity as follows:
    1. Enter a value in the Claim capacity box to define a maximum number of carriers that can move to the decision zone at the same time.
    2. Click Load products from the Load/unload option list.
    3. Click OK when done.
  9. Click the second decision point and click Edit SLA Resource in the context toolbar that appears.
  10. In the Edit Decision Point dialog box that appears, create an unload activity as follows:
    1. Enter a value in the Claim capacity box to define a maximum number of carriers that can move to the decision zone at the same time.
    2. Select Unload products from the Load/unload option list.
    3. Click OK when done.

Two zones to load and unload products are now defined on the conveyor. The zones are identified by red arrows on the image above.



You can now define a product zone on the carriers to specify the number of products to be loaded and unloaded. For more information, see Add a Product Zone.

Route Products on Specific Branches of an Intersection

You can define routes on a Power and Free conveyor to direct products on specific branches of an intersection.

  1. Open a Power and Free conveyor similar to the one below.

  2. From the Programming section of the action bar, click Pnf Routing Definition .
  3. Select a pathway and then a point on the conveyor before the intersection.


    A Power and Free decision zone is created on the pathway selected. The Define Pnf Routing dialog box appears, letting you specify routing parameters.

  4. In the Define Pnf Routing dialog box, click Select end points, and select another point after the intersection.


    A Power and Free decision zone is created on the selected point. A brown pipe appears in the work area and identifies the route defined.

  5. In the Define Pnf Routing dialog box, specify the route options, such as:
    • Priority: routes carrier from a decision zone to a target decision zone based on priority value. This option is set by default.
    • Product based: routes carrier from a PnF decision zone to different segments, based on the type of product on the carrier.
    • Define Traffic control: when selected, creates a traffic control area that limits the number of carriers in that area. You can edit the value in the box that appears in the work area, located at the end of the traffic control area.
  6. Continue in the same way to define routes on other branches.


    Brown pipes appear on all the branches, identifying routes. Blue pipes also appear, identifying traffic control areas.

Tip: To edit a route, click Pnf Routing Definition and select the route to edit in the list that appears in the Intersection list panel.

Optimize the Traffic Routing

You can specify a maximum number of carriers to circulate within the same segment of a Power and Free conveyor, by defining a clearance area. This avoids carriers to accumulate on the conveyor.

  1. From the Programming section of the action bar, click Pnf Clearance Area Definition .
  2. Select a pathway and then a point on the conveyor to define the clearance area start point.


    A Power and Free decision zone is created on the pathway selected. The Define Clearance Area dialog box appears, letting you specify clearance parameters.

  3. In the Define Pnf Routing dialog box, click End point, and select another point on the conveyor to define the clearance area end point.


    A Power and Free decision zone is created on the selected point. A colored pipe appears in the work area, identifying the clearance area.

  4. In the Define Pnf Routing dialog box, enter a value in the Capacity box to specify the number of carriers allowed on the clearance area at the same time.
  5. Continue in the same way to define other clearance areas.

Tip: To edit a clearance area, click Pnf Clearance Area Definition and select the area to edit in the list that appears in the Clearance Area list panel.

Prepare the Carriers Before Simulation

To simulate carriers, you must define a transfer activity on each carrier attached to the conveyor.

Before you begin:
  • The carriers in session must have a port defined. You can define ports in Equipment Design.
  • Define a product zone on a carrier using Add Product Zone. Make sure to select the Apply all instances check box to create a product zone on all the instances of the selected carrier. For more information, see Add a Product Zone.
  1. From the Programming section of the action bar, click Generate Transfer Activity .
  2. Select the conveyor.
    The product zone previously defined appears on the conveyor. The Add the Product that flows contextual command and a dialog box appear. The dialog box displays the list of existing ports. In our example, no port is found.
  3. Click Add the Product that flows and select a product to be loaded on the carrier.
  4. Click OK when done.

Transfer activities are automatically created on all instances of the selected carrier. Carriers are now defined as resources. You can edit them and simulate them.

Simulate Power and Free Conveyors

You can simulate Power and Free conveyors and collect statistics such as carrier state times.

  1. Click Play in the Compass and select Discrete Event Simulation from My Play Experiences.
    The Power and Free conveyor flow is simulated.
  2. Click a resource such as a carrier and expand the Chart Details area in the panel that appears.
    A panel appears with information on products and state times, specific to the selected carrier.
  3. Optional: Click Open HTML Report .
    A panel appears with detailed information on the selected carrier.