The MES system has to be connected to different communication partners to fulfil its function as a data hub. This requires numerous interfaces.
On the one hand, machine interfaces are required that provide information concerning machine data acquisition (MDA) or traceability, permit bidirectional data exchange with DNC mode or allow to download control configurations. Despite considering the diversity and individuality of single machines and facilities, a respective interface is available in most cases. However, diversity is slightly mitigated by a manageable number of established controls of reputable manufacturers and its communication protocols as well as by increasingly widespread communication protocols, such as OPC-UA.
ERP interfaces in general
On the other hand, the MES system almost always communicates with an ERP system, too, that provides order information for manufacturing. About 800 different ERP systems are on the German market. Nevertheless, the type of interface can usually be broken down to a few communication standards such as database tables, file transfer, XML – to mention the most important ones.
In addition, there are a few standard interfaces of leading ERP system providers. SAP offers a certification program for SAP-PP-PDC – which is one of the most important interfaces.
Due to its functionality it is limited to exchange order data and to provide a few master data which is by no means sufficient for detailed scheduling and planning within the MES system; data transmission of significantly more master data would be required for this purpose.
Thus, FASTEC programmed its own function modules that are conformable with the Guideline Best Practices ABAP Programming of the DSAG (German-speaking SAP user group). These function modules are of high performance and can be quickly adapted by FASTEC without SAP assistance. For data re-writing, the function modules use the SAP standard functions (IDocs).
If other IT systems are involved in production processes (such as QA systems, tool setting systems or document management), corresponding interfaces might be essential. Due to the wide variety of different systems and manufacturers, no general statement can be made. However, many of these systems provide interfaces based on a file or a database.