Due to the importance of inventory and order accuracy levels, the use of automated putaway and picking systems in the warehouse have gained in significance in recent years. The control of material flow in many storage areas is no longer carried out manually but by autonomous warehouse control units (WCUs). The task of the WCU is to control and monitor automatic loading and unloading devices and conveyer equipment used for handling the materials.
Using the WCU Interface via REMOTE FUNCTION CALL
SAP provides an interface that supports bi-directional data transfer between WM and automatic storage and retrieval systems (AS/RS). With this interface, there is a wide range of scenarios for using automatic applications -- from fork lift control systems, that receive the movement orders, to fully automated warehouses, that can optimize the movement orders and even manage individual storage bins.
The interface to the Warehouse Control Unit supports the following functions:
SAP R/3 _ External system
- Transmitting transfer order when they are created
- Releasing groups for multiple processing
This triggers the start of transfer order processing in the external system.
- Cancellation requests
This transmits either the transfer order cancellation itself or the requirement to cancel a transfer order depending upon the system that assigns storage bins.
- Sending inventory document list (for physical inventory)
External system _ SAP R/3
- Creating transfer orders (storage bins are assigned by the external system)
- Confirming transfer orders (confirms completion of physical movement)
- Canceling transfer orders (the external system can initiate this only if the transfer order has not yet been confirmed)
- Blocking bins for receiving stock (due to malfunction of automatic fork lifts etc.)
- Creating and changing transfer requirements (useful, for example, when planning transfer orders for using materials in production at a later time)
- Receiving and posting the count results of a physical inventory
- Moving storage units
Technically, this interface is based on transactional REMOTE FUNCTION CALL. Data is transmitted in IDoc (intermediate document) format. The actual communication is supported by ALE (Application Link Enabling), that offers logical error handling as well as a finely-tuned monitoring capability.
For this interface, you need to create C programs to send and receive data. SAP certifies partners for this interface which makes it possible to customize the system based on individual needs.
Using the WCU Interface via CPI-C and QAP-I
Prior to Release 3.0, the QAP-I interface was used for the link between automated storage and retrieval systems and WM. The QAP-I interface will continue to exist as an optional interface, however, the maintenance of this interface will only remain in effect for a short time. Therefore, all new projects should only use the ALE interface.