Table of Contents
Advertisement
Operating the Controller - CPU 41x-2 PCI
4.2
Restart Options for the Controller
4.2.1
Selecting the Restart Method
The restart method determines which startup OB the controller executes whenever
a change from STOP mode to RUN mode occurs. The startup OB allows you to
initialize your STEP 7 user program and variables. The CPU 41x-2 PCI
supportsthree restart methods:
•
Warm restart: The controller executes OB 100 before starting the free cycle
(OB 1). A warm restart resets the peripheral inputs (PII) and places the
peripheral outputs (POI) into a pre-defined safe state (default is 0). A warm
restart also saves the current value of the retentive memory areas for bit
memory (M), timers (T), counters (C), and data blocks (DBs).
•
Hot restart: All data areas (timers, counters, bit memory, data blocks) and
their contents are retained. The controller executes OB 101, reads in the
process input image, and then continues processing the user program at the
position where it was last stopped. A manual hot restart is only possible with
STEP 7.
Requirement You must enable the hot restart beforehand in STEP 7/HW
Config.
•
Cold restart: The controller executes OB 102 before starting the free cycle
(OB 1). Like a warm restart, a cold restart resets the peripheral inputs (PII) and
changes the peripheral outputs (POI) to a pre-defined safe state (default is 0).
A cold restart resets the retentive memory (M, T, and C) to their default values
(DB).
You specify the restart method to be performed automatically after Power
Off/Power On in STEP 7. The automatic restart method is stored in the
configuration (system data) for the controller that you download with your STEP 7
user program.
Whenever you click (using the left mouse button) the RUN mode selector position
on the panel to change from STOP mode to RUN mode, the CPU 41x-2 PCI
performs a warm restart, executing OB 100.
To select a specific restart method, choose one of the following options to change
the controller from STOP mode to RUN mode:
•
Select the CPU > RUN menu command to change the controller from STOP to
RUN mode.
•
Right-click (using the right mouse button) the RUN mode selector switch
position.
Both of these actions display the Restart Method dialog that allows you to select
either a warm or cold restart.
Note
If you have configured the confirmation security option, you must
acknowledge a confirmation dialog before the controller panel displays the
Restart Method dialog.
58
Hardware Installation and Operating Manual, Edition 02/2006, A5E00273194-02
Windows Automation Center, WinAC Slot Version 4.0
Advertisement
Table of Contents
