A
GFK-2731
Chapter A
A-31
A 13 Behavior in the event of an error
Error messages
Errors that occur on the safe devices can be detected using process data, function blocks,
and device LEDs.
These error messages can be evaluated in the standard application program or can be
displayed by means of a visualization.
Service information
In addition to error messages, service information can also be output. This information
takes the form of device message warnings that do not affect the safety function. These
warnings are either unacknowledged messages or messages that are acknowledged via
the controller.
Error classes
The response of all devices connected to the system and the safety functions to an error
depends on the error class detected.
There are 3 different error classes in the VersaSafe system:
– Critical system and device errors
– Parameterization and configuration errors
– I/O errors
A distinction is made based on:
– The severity of the error
– The reciprocal effects on other components in the system
– The acknowledgment and restart options
Acknowledgment
The acknowledgment of an error is an intentional user action (controlled via the standard
application program) with the aim of showing the system (or subsystem) that an error has
been removed and that the system (or subsystem) can reactivate the faulty component.
Errors affecting a VersaSafe island are acknowledged via the acknowledgment register of
the IC220SDL953 (see "Dev-Ack-LPSDO (acknowledgment)" on page A-19).
A 13.1
Critical system or device errors
All errors that are detected and immediately switch the device to the failure state are
assigned to this class.
They include:
– Hardware faults (detected by selftests within devices)
– Parameterization and configuration data errors (detected via the CRC)
– Control flow/program sequence errors within the firmware of a device
Errors in this class are usually errors within the system, the hardware, or the firmware,
which were not caused by the user and cannot be removed (device-specific exceptions are
possible).
It is not possible to acknowledge the error or continue operating. The affected devices can
only be restarted via a voltage reset. If the power on selftests are successful following a
restart, the system can continue to operate.
For instructions on how to proceed in the event of an error, please refer to "Parameter-
