User Manual
Appendix A
GFK-2843A
Jan 2020
VersaSafe system
91
•
Transmission errors
•
Data inconsistencies
•
Exceeding the transmission time over the set TFWD
•
Standard control system in the stop state
After a communication error is detected, the transmitted value assumes the substitute
value “0”. The affected safety function switches to the safe state. If a communication error
is no longer detected, an “operator acknowledge request” is displayed for the user. Once
the communication error has been acknowledged, the actual user data is transmitted
again.
Note:
Acknowledgment of communication errors
Communication errors may only be acknowledged by an intentional user action (e.g.,
acknowledgment button). They may not be acknowledged automatically from the
application program.
If communication errors occur more than once every 8 hours, the transmission path
quality must be improved.
A-11.4
I/O errors
All errors that can occur and are detected within the I/O devices connected to the safe I/O
devices are assigned to this class. They include, for example:
•
Short/cross circuits at the inputs or outputs
•
Other application-specific errors
These errors are usually indicated in the operating phase of the system. When an error is
detected, the affected input or output is disabled and a diagnostic message is sent to the
IC220SDL963 and the standard control system. The standard system remains ready for
operation. Ongoing operation of the application depends on the application itself.
I/O errors can be acknowledged individually by the user in the standard application
program.
A-11.5
Application errors
All errors that can occur within the safety logic configured in VersaConf Safety and can be
detected and acknowledged by the safe functional blocks are assigned to this class.
They include, for example:
•
Implausible signal states at the inputs (e.g., discrepancy error, incorrect muting
sequence or static state at the reset input)
•
Implausible parameter combinations
