This blog post helps to understand the SAP EWM MFS, its components and how it can help to manage an Automated Warehouse in combination with EWM LOSC without 3rd party Warehouse Control Unit.
This blog covers the following aspects:
- Understanding MFS
- SAP EWM LOSC
- SAP MFS Scenario
- SAP MFS Components
- Telegram Interface
- Solution Architecture
- Solution Overview
- Implementation Steps
- Configuration
- MFS Simulator for testing
- SAP MFS Master Data
- Next part
Understanding SAP EWM MFS
“MFS is out-of-the-box feature in SAP EWM to control the movement of fully automated Warehouse without 3rd party WCU or ASRS system”
MFS Requirement: In many warehouses today, goods are moved without any human interaction on longer distances via conveyers or carousels. In high-rack storage, you often have a fully automated storage and retrieval system.
MFS supports automation by the feature mentioned below.
• The material flow system (MFS) enables you to connect an automatic warehouse to SAP Extended Warehouse Management without the need for an additional warehouse control unit.
• SAP EWM communicates directly with the control level.
• 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.
SAP EWM LOSC (Layout Oriented Storage Control)
• Goods in your warehouse might not travel directly from a source storage bin to a destination storage bin, but rather travel via intermediate storage bins due to the physical layout of the warehouse.
• In Extended Warehouse Management, you use the layout-oriented storage control to describe these intermediate storage bins.
• In case of automated storage and retrieval systems, you need identification points and pick points to “connect” these systems to the rest of your warehouse.
• Examples for Warehouse require LOSC – Multi-level warehouse with elevator, warehouse with conveyors or robots.
More details can be found in the below SAP documentation
Reference:
MFS Scenario
- Cranes are used for movement of goods within aisles and no human intervention required for put-away or picking of goods.
- PLC controls the movement of cranes.
SAP MFS Components:
In the MFS, the warehouse to be controlled is mapped via the following components:
• Programmable logic controller (PLC)
PLC is the underlying real-time system controlling the physical transportation of HUs on conveyor systems and their components. It evaluates signals from the connected automatic storage retrieval/conveyor system or other controls and activates or deactivates motors, appliances, sensors, readers, and so on.
• Communication channel
Communication channel is the connection for transmission of messages between MFS and PLC, defined by an IP address and a port. You can use several channels to communicate with the same PLC.
• Communication point
Communication points are stations in the storage retrieval system at which it communicates with the PLC. Here, the PLC registers HUs (on the basis of scanner information or material flow tracking) and awaits new destination specifications. Every communication point is a storage bin in SAP EWM.
• Conveyor segments
Conveyor segments physically transport handling units (HUs) from one communication point to the next. You assign conveyor segments to your start and end points in layout-oriented storage control.
• Resource
MFS resource is a vehicle that transports an HU from one communication point (or storage bin) to another.
Telegram Interface:
Telegram interface is used to send and receive message between SAP EWM MFS & PLC.
To execute warehouse tasks, the EWM system generates telegrams and sends
these to the appropriate PLC.
Telegram type is used to identify the type of message being communicated.
Below are commonly used telegram types:
ABAP Dictionary structure is used to define the telegram message structure.
ABAP Function module is used to process the telegram message which are called as MFS Actions.
When a new WT is created, it is hardcoded that system should first generate telegram message with type ‘WT’.
Telegram Category 'E' is used during new MFS task creation.
Telegram Category 'E' is hardcoded in the type group 'WMEGC'.
Get Telegram Type from the configuration table
Below is the configuration table screenshot.
Below are the reply telegram messages from PLC based on the messages from SAP EWM MFS.
Solution Architecture Overview:
Solution Overview:
· Warehouse task in EWM is relevant for automatic movement if the storage type role is ‘J’ and the WT queue is assigned to PLC and MFS resource.
· Telegram message triggered from SAP MFS to PLC and PLC sends an acknowledgement message to SAP MFS as an handshake upon receiving the telegram message.
· PLC assigns the task to resource for physical movement based on information from WT.
· Resource performs the actual goods movement.
· PLC triggers telegram message to SAP MFS for the WT confirmation.
· SAP EWM MFS sends acknowledgement telegram message as an handshake with PLC.
Implementation Steps:
· Define Storage Type
· Define Warehouse Process Type
· Configure LOSC
· Define PLC Interface Type
· Define PLC
· Define Communication Channel
· Define Communication Points
· Define MFS Queues
· Define Telegram Structure
· Define MFS Actions
· Find MFS Actions
· Error Handling
Configuration:
Storage Type Definition
Configuration Path: SPRO IMG --> SCM Extended Warehouse Management --> Extended Warehouse Management --> Master Data --> Define Storage Type
ID Point Set-up
Storage Type
Storage Section
Identification Point Bin
Warehouse Process Type Definition
Configuration Path: SPRO IMG --> SCM Extended Warehouse Management --> Extended Warehouse Management --> Cross-Process Settings --> Warehouse Task --> Define Warehouse Process Type
LOSC Configuration
Configuration Path: SPRO IMG --> SCM Extended Warehouse Management --> Extended Warehouse Management --> Cross-Process Settings --> Warehouse Task --> Define Layout-Oriented Storage Process Control
Define PLC Interface Type
Configuration Path: SPRO IMG --> SCM Extended Warehouse Management --> Extended Warehouse Management --> Material Flow System (MFS) --> Master Data --> Define PLC Interface Type
Define PLC
Configuration Path: SPRO IMG --> SCM Extended Warehouse Management --> Extended Warehouse Management --> Material Flow System (MFS) --> Master Data --> Communication Channel --> Define Communication Channel
Define Communication Channel
Configuration Path: SPRO IMG --> SCM Extended Warehouse Management --> Extended Warehouse Management --> Material Flow System (MFS) --> Master Data --> Define Programmable Logic Controller (PLC)
Define Communication Point
Configuration Path: SPRO IMG --> SCM Extended Warehouse Management --> Extended Warehouse Management --> Material Flow System (MFS) --> Master Data --> Define Communication Point
Define MFS Queue
Configuration Path: SPRO IMG --> SCM Extended Warehouse Management --> Extended Warehouse Management --> Material Flow System (MFS) à Master Data --> Define MFS Queue
Define Telegram Structure
Configuration Path: SPRO IMG --> SCM Extended Warehouse Management --> Extended Warehouse Management --> Material Flow System (MFS) à Telegram Processing --> Define Telegram Structure --> Define Telegram Structure for PLC Interface Type
Define MFS Actions
Configuration Path: SPRO IMG --> SCM Extended Warehouse Management --> Extended Warehouse Management --> Material Flow System (MFS) --> Telegram Processing --> Define MFS Actions
When WT confirmation (WTCO) telegram is processed by MFS action FM, system performs the following action.
- Post HU to CP resp. storage bin (if not yet there)
- Triggers follow up task (layout oriented)
Find MFS Actions
Configuration Path: SPRO IMG --> SCM Extended Warehouse Management --> Extended Warehouse Management --> Material Flow System (MFS) à Exception Handling --> Assign Telegram Errors to PLC Errors
Maintain the telegram type for warehouse and assign it to MFS action.
Error Handling
Configuration Path: SPRO IMG --> SCM Extended Warehouse Management --> Extended Warehouse Management --> Material Flow System (MFS) --> Telegram Processing --> Find MFS Actions
PLC can send this error code in the handshake telegram message as Communication Error.
MFS Simulator for Testing
SAP system offers a RFC module to test the communication when we do not have the real connection with the PLC.
Simulation is implemented in the function module /SCWM/MFS_SIM_RECEIVE.
Assign the simulation RFC module when maintain the PLC in master data section.
If your wish to test it with PLC without physical movements, PLC emulation can be used.
SAP MFS Master Data
· Maintain PLC
· Maintain Communication Points
· Maintain MFS Resource
Maintain Programmable Logic Controller
SAP Easy Access: SAP Menu --> SCM Extended Warehouse Management --> Master Data --> Material Flow System (MFS) --> Maintain Programmable Logic Controller
Set communication layer as ‘Proprietary Communication Layer’ for simulation.
Set the simulation Remote FM in the Sending FM.
It is recommended to use SAP ABAP Push Channel as Communication Layer in the real time.
Maintain Communication Points
SAP Easy Access: SAP Menu --> SCM Extended Warehouse Management --> Master Data --> Material Flow System (MFS) --> Maintain Communication Points
Assign storage bin to communication point.
Maintain MFS Resource
SAP Easy Access: SAP Menu --> SCM Extended Warehouse Management --> Master Data --> Material Flow System (MFS) --> Maintain MFS Resource
Maintain resource and assign to queue.
Next part of this blog covers:
- Inbound process with MFS (link below)
https://github.com/dominik-tylczynski/mfs-plc-sim
i'm connecting to PLC but connection is always lost after sending some telegrams how to deal with it?
One more question please, how is CP01-CLAR defined in the define communication point screen? thanks
Great info. One question how was PLC consys2 defined?