Material
Flow System (MFS) 
Purpose
The Material Flow System (MFS) enables you to connect up an automatic warehouse to Extended Warehouse Management (EWM) without the need for an additional warehouse control unit.
You can set up the MFS in such a way that warehouse tasks (from an identification point to a storage bin in an automatic high-rack storage area, for instance) are subdivided into smaller tasks. These are passed on step by step to the programmable logic controller (PLC) responsible in each case via telegram communication. The putaway and removal from storage of handling units (HUs) can thus take place without the use of another software system.
You can define capacity limits for communication points, conveyor segments, or resources. The EWM system then holds back tasks for the PLC as soon as these limits are exceeded. The same applies if the PLC reports that one of the individual elements of conveyance (vehicles, legs, communication points) are subject to malfunction.
A warehouse management monitor that is supplied as part of this package enables you to track, evaluate, and influence the process.
Introductory Notes
Make the Customizing settings described under Setting Up the Material Flow System.
Integration
The MFS is integrated within EWM. It is connected to one or more PLCs.
Features
If you use EWM to manage an automatic warehouse, you can use the following functions:
● Automatic identification of HUs using scanners on the automatic storage retrieval facility.
● Automatic diversion of HUs that cannot be stored (incorrect contours, excessive weight, unidentified)
● Fully automatic putaway of HUs in the storage bin via any number of interim steps. These interim steps are represented by communication points.
● Malfunctions reported by the controls taken into account
● Capacity limits for communication points, conveyor segments, and vehicles taken into account
● Reduction in empty traveling paths for stacker cranes through interleaving
● Goods-to-man picking principle
● The stocks are also available for deliveries during transportation within the system.
● Stable telegram communication between EWM and PLC via parallel, bidirectional communication channels
The warehouse management monitor provides you with the following options:
● Tracking of current state of system
● Evaluation of telegrams and response times
● Determination of current location of HUs and identification of associated warehouse tasks
● Determination of telegram traffic relating to individual HUs or warehouse tasks
● Stopping or restarting of communication with regard to individual controls
● Locking of communication points, segments, or resources
● Resending of telegrams where necessary
● Manual confirmation of warehouse tasks
You can call up
logs for exceptions via the 
alert monitor. The
system generates these logs if communication with a PLC was interrupted and
EWM initiated an automatic restart of the communication channel. You can link
these exceptions with follow-on actions (such as notification of a control
station).
A further
evaluation allows the accessing of system logs by the
system administrator. An example of something that might be logged by the
system is when a warehouse task pending transport was not sent to the PLC (due
to insufficient capacity at the next communication point or due to a
malfunction, for example).
For more information, see MFS in the Warehouse Management Monitor and MFS in the Alert Monitor.
For better understanding, the graphic below illustrates a possible automatic storage retrieval system in an example warehouse:
This example warehouse consists of an automatic high-rack storage area with three aisles and automated putaway and removal. A distribution trolley links the putaway and picking area with the high-rack storage area.
From the MFS standpoint, this warehouse is operated with four controls. Three are for the stacker cranes (green) and one is for the distribution trolley and the conveyor lines of the preliminary (prestorage) zone (blue).
The warehouse has a single depth, the distribution trolley and stacker cranes each have just one load handling attachment (LHA).
The following graphic shows an example of the material flow in this example warehouse:
This example comprises the following processes:
- Putaway
- Removal from storage of full pallets
- Supplying the picking bin
- Putback
- Conveying off the pick HU
- Diversion to clarification bin