Siemens SIMATIC S7-GRAPH Manual page 172

Notes on Configuration
Representing the Mode in the Sequencer
If, for example, a selector switch on the control panel supplies the signals
automatic, inching and manual as individual single signals, only relatively simple
logic is required to derive the mode signals for the sequencers and for the
underlying drives of the units as shown in principle in the following diagram.
Process
enable
The modes selected at the console are passed on to the sequencers when
Process_enabled is active. If Process_enabled is not set, the modes of the
sequencers are switched to SW_MAN and step enabling is suppressed.
In the automatic or inching modes, the automatic mode is set for the unit functions.
The manual mode is passed on directly. If Process_enabled is not set, both modes
are canceled and movements stopped. The functions of the unit groups are
represented in an FB created with LAD/FBD or STL.
14-6
Mode
selector
Mode setting
Seq_Auto
&
Autom.
Seq_Inch
&
Inching
&
Seq_Man
. 1
Manual &
Unit_Hand
. 1
Unit_Auto
S7-GRAPH for S7 300/400 Programming Sequential Control Systems
FB sequencer n
SW_AUTO
SW_TAP
SW_MAN
FB sequencer 1
SW_AUTO
SW_TAP
SW_MAN
FB unit group n
Automatic
Manual
FB unit group 1
Automatic
manual
C79000-G7076-C526-01