Modula Link is a software tool that allows an external Host System to have low-level control of a group of LIFT OS machines using a set of commands which are communicated over a TCP/IP sockets channel. Modula Link acts as the communications server: it opens a TCP port (configurable) and waits to receive commands; when it receives a valid command from the external Host System, it processes it and responds. Modula Link can be configured to handle commands from a single client (Mono-Client Communication) or from several clients (Multi-Client Communication).
When the Host System needs to call a tray, it uses the appropriate command. The moment the tray is ready in the bay, Modula informs the ERP, which proceeds with the operation and, on completion sends a command to return the tray to its location. Modula receives only the tray call request. The console shows the tray is ready, but does not inform the operator; it is the job of the ERP to inform the operator of the activities to carry out and asks for confirmation of the action. Typically the picking tool used is an RF terminal, an external PC being less common. With precise, real-time control of the warehouse, an ERP system can be equipped with a series of advanced logistics functions.