Programming sequence controls
SIMATIC S7-GRAPH is based on the STEP 7 programming software. It is used for describing procedures with alternative or parallel step sequences. The procedures are configured and programmed clearly and quickly in a standardized method of representation (to IEC 61131-3, DIN EN 61131).The process is described graphically, and divided into individual steps with an easily comprehensible scope of functions.
Actions can be defined for the steps, and their execution controlled. Transitions control the conditions required for the next step. Interlock and monitoring conditions are defined for each step.
Area of application
A typical example of a sequential operation is a drilling procedure with the following steps:
Drilling machine ready
Start drill motor, optionally coolant pump on
Coolant pump off, motor off
Open the clamp
For programming compliant with IEC 61131-3 and PLCopen Base Level, the following functions are available.
Additional benefits over LAD, FBD, and STL:
LAD, FBD and STL focus on logic control. S7-GRAPH places more importance on the pfrocess sequence.
Clear graphical representation of the process using sequencers, providing easy maintenance and modification adaptation of the programs if required.
Process error troubleshooting with integrated diagnostics functions; expensive downtimes during production are minimized.
Design and functions
Flexible sequencer structure:
Simultaneous and alternative branches,
jumps within the sequencers,
step enabling and disabling.
Selective processing of steps. The processing time of a sequencer is thus independent of the number of steps.
Synchronizing automatic and manual operation. The process is not synchronous anymore when it was placed into a different state manually.
S7-GRAPH supports the locating of synchronization points for restarting automatic operation. To do so, the relevant steps are marked. Step-enabling conditions or interlocks can be defined as criteria.
S7-GRAPH is part of the STEP 7 Professional Software package yet also available separately. Customers that already use STEP 7 can change to STEP 7 Professional by purchasing a POWERPACK. A valid STEP 7 license is needed for this upgrade. Software Update Service is offered for the STEP 7 Professional package as well.