Solar Buffer

Development of a user interface for the buffer storage of a solar module

Sector: photovoltaics

Buffer storages are integrated in the production lines of solar modules. The buffers serve as a temporary storage of glass substrates. InSystems Automation GmbH developed the graphical user interface which controls the buffer storage for a manufacturer of solar modules.

Projekt Description for all three Buffers

Alle data in the buffer storage are transmitted periodically to a MES (Manufacturing Execution Systems). The substrate storage happens in the buffers, which are divided into three systems, so that the plant can produce energy during a failure. In the time, when the operator maintains the failed plant,  the buffers are split into two skid lines, so that the production still goes on.

MLC (Material Flow Control)

The PLC (Programmable Logic Controller) controls and manages the buffer storage, so that the MLC helps visualizing the buffer system and the substrate data. It represents the interface between the buffering system and the MES.

The installed MLC is provided as touch panel and the control elements are designed in order to allow a smooth operation. For alphanumeric input, a touch panel keyboard fades in.

The MLC graphical user interface consists of:

  • A title bar on the top (Name of the system, date and time, logos)
  • Control elements in different register tabs (layout, buffer archive, substrate archive, messages, diagnostic, OEE and system)
  • A status bar in the right column ( interface connection status, operating mode, user login button)

Visualizing of the Buffer System

The user interface displays the system in the layout. Therefore, the single boxes within the buffer system can be shown in detail. Visualizing the buffer positions allows the control of the shuttle car , which is otherwise not visible because of the closed construction of the buffer system. During manual mode, the actual position of the shuttle car can be seen. The operator can also recognize, whether it docks on a roller conveyor and in which direction a roller conveyor gets driven. The input of the box number creates a list of the contained substrates. Additionally, the operator can look for a substrate name in the archive. If this substrate exists in the database, he gets the corresponding box, the access to the buffer, the disposal date and the quality.

PLC Interface

Regardless of the used communication hardware, the data exchange between PLC and MLC  is implemented by a data block interface.  In this scenario, the PLC is always the server and the MLC the client.  The MLC communication object must provide the appropriate  S7 communication layer.

MES Interface

A MES interface was implemented  according to SEMI SECS/GEM. GEM allow a basic communication and can link following GEM capabilities between buffer system and MES:

  • Material tracking events
  • Equipment data
  • Documentation