Design and Implementation of a Warehouse Control System (WCS) for Automated Warehouse Operations

The warehouse initially used a simple inventory (进销存) system focused on stock, procurement and sales, which proved insufficient as business grew, prompting the development of a dedicated WMS tailored for second‑hand goods and the introduction of automation equipment.

The newly built Warehouse Control System (WCS) sits between the WMS and PLCs, receiving commands from the WMS, forwarding them to PLCs to drive hardware, and reporting real‑time status back to the WMS; the architecture diagram is shown in the accompanying image.

To communicate with diverse hardware, the WCS supports four protocols: HTTP for simple request‑response devices such as sorting chutes; Server‑Sent Events (SSE) for server‑to‑client push scenarios like automatic pick‑task printing; WebSocket for full‑duplex communication required by devices such as illuminated shelves, with hot‑standby, message‑loss handling and heartbeat reconnection illustrated; and TCP for devices that only expose a raw TCP interface, e.g., a camera used on the outbound line.

System monitoring is provided via a WebSocket client monitoring page that displays connection status and hardware configuration, and integrates with Prometheus to track metrics such as message loss and retry counts, as shown in the monitoring screenshots.

Device empowerment is described for inbound (scanning, slot selection, quantity entry, inventory update) and outbound (picking, seeding, verification) processes, with diagrams showing how automation reduces manual steps and increases throughput; additional local devices such as an abnormal‑removal shield and an automatic packaging machine are also presented.

In conclusion, rapid business growth demanded higher warehouse capacity, leading to the deployment of automated equipment and a tightly coupled WMS‑WCS solution that enhances efficiency, reduces labor, and supports continued scaling.