C-DIAS SAFETY CPU
CSCP 012
1.6
Page 29
a) During restart, the Safety CPU first runs the POST (Power On Self Test). In the
POST, whether the Safety CPU is configured or not is determined. If the Flash
memory in the Safety CPU is empty, it changes to the service mode and switches
the status LED (ST) to continuously on.
b) If the Flash memory of the Safety CPU contains a configuration, it goes into the
idle / Check Configuration Mode. Thereby, an attempt is made to distribute the
configuration; the ST-LED blinks during this process.
c) If the configuration is successfully distributed, the Safety CPU either goes into the
Operational mode or the Temporary Operational mode depending on whether or
not the configuration has already been validated. If the System was already vali-
dated, the ST-LED turns off and the RN-LED lights. If the system has not been
validated, both LEDs light simultaneously.
d) If for whatever reason the distribution of the configuration is still not successful,
the Safety CPU switches to the Error mode and the E-LED lights
e) When the Safety CPU remains in the idle / Check Configuration Mode for a long
period of time (ST-LED blinking) without switching to the Error mode, it is an indi-
cation that the bus communication is malfunctioning. In this case, the PLC will re-
main in the error status and must be restarted.
f)
A change to the error status can also occur from the POST and (Temp.) OP mode
if other (internal) errors are detected or errors in remote modules occur. The anal-
ysis of these errors however, requires the use of the SafetyDesigner.
Configuration distribution error
If the Safety CPU fails to distribute the configuration, the cause can be traced to one or
more of the following errors.
•
The configuration and the physical topology do not match
•
One or more modules are missing
•
More than one module was exchanged
•
Communication error with a remote module
•
The module to be configured is in error status
