What is GRAFCET?

GRAFCET is a standard valid in Europe (DIN EN 60848) which may be used to describe a control function or a machine.

 

GRAFCET is the abbreviation for

GRAphe Fonctionnel de Commande Etapes/Transitions.”

 

It means:

Step Transition function chart.

Example of a GRAFCET
GRAFCET Example

How is GRAFCET used in practice?

GRAFCET helps to guarantee the best possible, highly efficient working relationships between different professional groups (or disciplines):

The designer creates the GRAFCET and the mechanical engineer can use it to construct the requested machine. Then, the PLC expert writes a program which corresponds to this and the commissioning engineer can prepare the machine for operation. The system operator is better able to understand the machine’s processes using the GRAFCET and maintenance staff can remedy disruptions faster as the system’s functions can gauge faster.

 

This is the idea behind the standard at the very least.

 

Theory and practice do not overlap entirely

Things often turn out differently in reality:


Either no GRAFCET at all is created, as this is viewed as unnecessary additional work, or the GRAFCET is created but not synchronised with the programming.

 

After some time, the programming has nothing to do with the original GRAFCET.

GRAFCET Studio bridges gaps

To significantly increase acceptance of GRAFCET, it would be helpful to have a tool with which a GRAFCET could be designed and automatically converted into a PLC program.

 


These gaps will now be bridged using “GRAFCET Studio” software:

  • Design a GRAFCET
  • Simulate a GRAFCET on the PC
  • Automatically convert a GRAFCET into a PLC program and transfer it to the PLC

Using GRAFCET Studio, the description language GRAFCET therefore becomes a cross-platform programming language.