SmartPLC SafeLine with PROFIBUS slave interface
23
3.3.3
Monitoring and securing mechanisms
42296
>
System start / power on reset
42276
When the voltage supply has been applied, the safety module of AC412S automatically undergoes a
power-on built-in test (PBIT). The PBIT consists of the following routines:
Test and installation of the safety-relevant hardware modules
Test of the program, configuration and user data in SDRAM (CRC test)
If at least one of these partial tests is failed, the system reacts as follows:
The safety module goes into the safe state
The transition from the fail-safe PLC to the safe operation is prevented
An error message is provided in the online support centre (OSC) of the device
>
Normal operation
42297
During normal operation the safety module of AC412S continuously undergoes a continuous built-in
test (CBIT). The CBIT detects accidental hardware errors. It monitors all safety-relevant hardware
modules. The CBIT consists of the following routines:
Monitor the safety-relevant hardware modules with the required DC
Monitor all diagnostic data that is relevant for the safe functions
Monitor the program process
Depending on the error class the device triggers certain measures (
→
Error classes
(
>
3.3.4
Error detection and processing
42221
>
Error classes
42218
AC412S recognises the following error classes:
>
Fatal error
42222
The following errors are classified as fatal errors:
error in the device (temperature exceeded, soiling)
error in the channels
Response to fatal errors:
The safety module goes into the safe state (
→
Safe state
(