Selecting The Structure Of The Sequencer - Siemens SIMATIC S7-GRAPH Manual

Designing a Sequential Control System based on the Example of a Drill
Initial State
The initial state of the drill is defined as follows:
• The drill motor and cooling pump are stopped
• The carriage/drill is in the upper position
• There is no work piece in the clamping device
Functional Diagram - Drilling Sequence
The entire drilling sequence can be divided into the following sections:
• Insert work piece (manual)
• If required, set switch for coolant (depending on the material)
• Start the machine with the start button (drill motor starts up)
• Clamp the work piece with the selected clamp pressure
• Start the cooling pump (if coolant selected)
• Lower drill and carriage to the bottom target position (drill)
• Wait 0.5 seconds at lower target position (drill)
• Raise drill with carriage to upper target position
• Remove work piece, turn off drill motor and cooling pump
• Remove work piece (manual)
Element
Start
Clamping
device
Motor
Carriage
3.2

Selecting the Structure of the Sequencer

Before you write the program for the sequencer, you should include a concept
phase in which you break down the drilling operation into single steps. The basis of
the concept design is the technological drawing and the flowchart.
3-4
State
On
Off
running
stopped
up
down
S7-GRAPH for S7 300/400 Programming Sequential Control Systems
C79000-G7076-C526-01