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Industrial Automation



Defining the Carton Conveyors and Pick-to-Light

Defining the Conveyor Types

Naming the Zones

Defining the Conveyors

Placing the Devices

Setting the Compartment Sizes

Format of Pick Area Types

Defining the Pick Areas

Addressing the Pick Areas

Below is shown the fully configured carton conveyor and pick-to-light definition screen, as would be presented by the MS-DOS version of “Movement Controller”.

Screen dump from DOS version of
Movement Controller, showing the
screen use to define the carton conveyor and pick-to-light system, converted to
a “gif” file, thereby losing some of the colour definition

The following steps perform the definition of the carton conveyor system and picking areas:

  • Defining the types of conveyors. This provides the dimensions and speeds of the conveyor types, and, of course, assigning a type name so that a conveyor section may reference the type.
  • Defining the pick and dispatch zones. These tie the conveyors to the picking areas. The zones require a name and type.
  • Specifying the physical layout of the carton conveyor system along with its associated picking or dispatch zone (if relevant) and the identification of its motor (if any).
  • Placing the devices along the carton conveyor system.
  • Defining the standard picking compartment sizes. When the pick areas are later defined, they will be matched to these to determine what type and quantity of product they can handle.
  • Defining the different formats of the pick areas.
  • Specifying the physical layout of the pick areas, referring to the previously defined formats.
  • Setting the addresses for the pick area divisions.

The lamps on the pick areas are intended to indicate whether the pick areas are stocked and whether picking is under way. During the system definition, they will normally reflect whether the pick areas have been addressed.

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Defining the Conveyor Types

A conveyor type is defined by providing it with a name, the dimensions and pitch of its rollers, the speed of the conveyor and the overall width. A nominal carton length is also to be specified to allow the simulation to display the cartons.

The conveyor types are referenced by the conveyor sections and impact on the presentation of these conveyors and the simulation of the movement of cartons along these conveyors.

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Naming the Zones

A zone is defined by providing it with a name and indicating whether it is a picking or dispatch zone.

Pick areas and certain conveyor sections reference picking zones. The motion controller will be told what product is needed for which cartons. It will find the product in the pick area, and then know the zone it needs the carton to reach. By matching this to the conveyor section with the same zone reference it will know to where the carton is to be directed and what needs to be picked when it gets there.

One dispatch zone will be entered for each carton. Once the carton has finished its picking, the motion controller will need to guide the carton to the conveyor section referencing this dispatch zone.

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Defining the Conveyors

The carton conveyor system is defined by defining a series of conveyor sections. Each conveyor section is either straight or a constant radius curve, controlled by one only motor, though this motor may control several conveyor sections.

The conveyor section is defined by specifying the physical location of its left rear corner, the conveyor section, which feeds it (if any), the type of conveyor it is (these types set the non-length dimensions and the speed of the conveyor), which zone it services (if any), and which motor drives it (if any).

When specifying the conveyor, which feeds it, the referenced conveyor must actually feed it, not just end where it starts, as this information is used to generate the routing.

A straight section of conveyor is completely specified when the entry for its left rear corner is created and another conveyor section references it as feeding it. Should it not feed another conveyor, an “end” entry must be made, with the coordinates of the section's left front corner and referencing the section as feeding it.

A curved section of conveyor is completely specified when the entry for its left rear corner is created and a completely specified straight conveyor section references it as feeding it.

Once a conveyor section is completely specified its position can be interactively modified.

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Placing the Devices

The device types are predefined and include barcode readers, check weighers, tape sealers, diverters, draw bridges, pop-up stops, tape sealers, merges and diverges. To place a device, it must be given a name, a type, a conveyor section and a distance along the conveyor. Do not place the merges and diverges, as these are done in one keystroke at the end.

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Setting the Compartment Sizes

The compartment sizes are used to specify which products and what quantity the pick area divisions can accommodate. To define a compartment size, it must be given a name, a length and height.

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Format of Pick Area Types

By defining types of pick areas, with formats for each type, we reduce the effort, which would have otherwise been required to define the pick areas.

Here we give the pick area type a name, and three dimensions. We then divide the face of the pick area into locations.

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Defining the Pick Areas

The definition of the pick areas draws on the prior definition of the picking zones and the pick area types. To define a pick area, it must be given a zone, a name, a position (x and y) and access angle and a pick area type.

The position coordinates reference the front right hand corner of the pick area. This information, combined with the dimensions supplied with the pick area type definition and the access angle are sufficient to display the pick area on the conveyor diagram.

The pick area is displayed as a blue rectangle with a black edge around three of its sides. The fourth side is the side from which it is accessed.

This job is usually the most tedious/time-consuming part of the definition process. If the system is a large one, it may be worth placing a few pick areas in key positions, then exporting the appropriate records, editing them with your favourite editor to extrapolate to the remaining pick areas then importing the resultant file.

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Addressing the Pick Areas

Each division within each pick area must be given a unique address so that messages may be sent to it along a multi-drop communications channel.

The following steps perform this:

  • Setting an addressing pattern (Harness Wiring) for each pick area type.
  • Determine which pick areas are electrically adjacent to which.
  • Provide start addresses for each block of electrically adjacent pick areas.
  • Set the pick-to-light unit addresses into the database for each pick area division.
  • Write the pick-to-light unit addresses into the hardware of each pick area division.

The first three of these steps specify the algorithm for assigning addresses to the pick areas. The fourth step executes the algorithm to assign the addresses to the database for each pick area division, while the final step involves programming these addresses into the hardware.

For detailed information on how to configure the carton conveyor and the pick-to-light systems, please refer to the Operator's Manual section Enter or Modify the Carton Conveyors.

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