Start-Up Mode - Siemens CPU 948 Programming Manual

START-UP Mode

4.3

START-UP Mode

Mode change
Start-up types
COLD RESTART
WARM RESTART
No time monitoring of the
start-up OBs
Counters, timers, flags,
process images
BASP
Interrupts
Start-up in the multiprocessor
mode
4 - 16
The START-UP mode has the following features:
START-UP is the transition from the STOP mode to the RUN mode.
The CPU 948 has the following start-up modes:
- COLD RESTART ( manual or automatic)
- WARM RESTART (manual or automatic)
(You can select the type of start-up with operating elements and by
assigning parameters in DX 0)
The cyclic user program is processed from the beginning.
The system program calls OB 20 as the user interface.
The execution of the cyclic user program is continued from the point
at which it was interrupted.
The system program calls the following OBs as the user interface:
- OB 21 for a MANUAL WARM RESTART,
- OB 22 for an AUTOMATIC WARM RESTART.
The execution time of the start-up organization blocks is not
monitored. You can call other blocks within these OBs. Make sure
you avoid endless loops!
The values of counters, timers, flags and process images are handled
differently in the various start-up types (refer to Section 4.4.3).
The BASP signal (disable output command) is active. This disables all
the digital outputs (exception: in the test mode in multiprocessor
operation, the BASP is not activated - refer to Section 10.1.8).
The interrupts (normal interrupts, process interrupts, timed interrupts)
are disabled.
Starting up in the multiprocessor mode is described in Section 10.1.7.
CPU 948 Programming Guide
C79000-G8576-C848-04