Sorter

Sorter is a conveyor logic block that directs items based on a configurable selection. It accepts items from the back and either passes them forward (relative to its facing) when they match the selected item filter, or redirects them to the left and right outputs when they do not match. Sorters do not store items and transport them instantaneously through the block, so they behave differently from storage-capable blocks like Routers.

Unconfigured sorters (a “null” sorter with no selected item) always route incoming items to the side outputs. Because they have no internal item capacity and effectively unlimited instantaneous throughput, pairs or groups of null sorters can be used to create high-throughput splitters that instantly distribute batches across multiple output lanes without clogging. For example, two null sorters placed side-by-side form a compact 2:4 splitter that never crosses item lines; combining additional pairs yields 2:6 or larger split designs with full throughput. This property also makes sorter-based splitters superior to zipper splitters when preserving instantaneous throughput is required.

Sorters cannot be chained indefinitely. The game enforces a Max Consecutive limit that prevents items from traversing more than two consecutive sorters or gates in a row. If an item would have to pass through more than this limit, it will not enter the first sorter or gate on that path; if every possible direction would exceed the limit, the item will be blocked at the input. This rule prevents instantaneous long-distance transport chains and constrains how many sorters can be linked in sequence for routing logic.

Practical usage and interactions:

• Configure the sorter by selecting a single item type to let that item pass forward; all other items are sent to both side outputs. Unconfigured sorters send everything to the sides.
• Place null sorters intentionally to implement route splitters that preserve throughput and avoid crossing conveyors. Common designs use side-by-side null sorters for 2:4 splitting or stacked pairs for larger splits.
• Use sorters to funnel specific resources to production lines (e.g., direct coal forward to a combustion generator while other materials go sideways).
• Be mindful of the Max Consecutive limit: chains of more than two sorters/gates break routing and will prevent items from entering; design around this by inserting other conveyor blocks (like Routers) or routing junctions.
• Sorters do not clog and do not have item capacity, so they cannot be used as temporary buffers. For buffering, use storage-capable blocks such as Routers or Containers.
• The sorter’s description and behavior were clarified in later updates: it was changed to explicitly state that a matching item passes forward while non-matching items are output to the sides.