Siemens CPU 948 User Manual

5.7 Self-Test
5.7.1
Overview The CPU 948 contains integrated self-test routines in the system
program.
Activating/deactivating You can activate or deactivate the functions of the self-test using bits
in system data RS 137.
Time slice To reduce the cycle load caused by the self-test in the RUN mode,
only part of the self-test is carried out within a cycle (time slice). The
time available for the self-test can be set in RS 136 (refer to
Section 5.7.3).
What can be tested? The self-test routines can carry out the following tests:
WHAT IS TESTED? WHEN?
The user memory During OVERALL RESET
The BASP signal
(disable command output)
In the STOP mode
The hardware clock During COLD RESTART
The cycle time monitoring During START-UP
The address lines Cyclically in the RUN mode
The code of the system program
(checksum)
Cyclically in the RUN mode
The code of the STEP 5 logic
blocks in the user memory
(checksum)
Cyclically in the RUN mode
Self-Test
CPU 948 Programming Guide
5 - 34 C79000-G8576-C848-04

Siemens CPU 948 Specifications

General

Brand	Siemens
Model	CPU 948
Category	Controller
Language	English