ABB AC500-S Safety User Manual page 30

Overview of AC500-S safety PLC
FAQ - AC500-S safety PLC
● Can AC500-S safety modules be used in low-demand applications?
Yes.
● How to make the safety CPU address switch setting compliant to SIL 3 / PL e if one
wants to use its value in the safety application program?
One may want to change the safety CPU safety program execution path depending on the
safety CPU configuration switch setting, which can be read in the safety program using
SF_SM5XX_OWN_ADR function block. Changing the safety CPU safety program execution
path depending on the safety CPU address switch setting only is not always enough to
reach SIL 3 / PL e. One has to implement some additional mechanisms, e.g., to have a
second point-of-entry for program configuration setting on the application level. This can be
done, e.g., by reading some pre-configured (pre-saved) values from SD card on the non-
safety CPU. This additional pre-configured (pre-saved) value has to be transferred to the
safety CPU and compared against the safety CPU address switch setting before the safety
CPU address switch setting is accepted for the safety CPU safety program execution path
change. This way one can attain a higher functional safety level up to SIL 3 / PL e.
● In which types of applications are FBs like SF_APPL_MEASURE_BEGIN and
SF_APPL_MEASURE_END used?
These FBs can be used for time profiling of your safety application program, which is often
very useful for debugging purposes to find performance bottle-neck in safety applications.
For instance, to estimate the actual time taken by the safety CPU to execute a certain part
of the safety program logic.
● How can user data on the safety CPU be made persistent?
User data can be stored in the non-volatile flash memory of the safety CPU and read or
deleted from there using special FBs (SF_FLASH_WRITE, SF_FLASH_READ and
SF_FLASH_DEL).
● Can errors related to remote PROFINET/PROFIsafe safety modules be captured in the
diagnostic buffer of the non-safety CPU?
AC500 V2: Yes, you can use special diagnostic FBs to read diagnostic messages from
remote safety modules on the V2 non-safety CPU. These FBs can be found in the library
Profinet_AC500_V13.lib on the V2 non-safety CPU.
AC500 V3: The PROFINET/PROFIsafe related errors can be automatically collected in the
diagnostic buffer of the V3 non-safety CPU.
● Why does non-safety CPU reboot command not reboot remote safety I/O modules?
This behavior is as designed. Only central safety I/O modules will be re-initialized after non-
safety CPU reboot command. All remote safety I/O modules may not be re-initialized and
have to be acknowledged from the safety program to re-integrate them after non-safety
CPU and safety CPU re-initialization is finished. This behavior (re-initialization or not)
depends on PROFINET CI5xx setting and can be modified.
● Is ST to LAD/FBD conversion possible?
Yes, for simple projects involving basic instruction set the conversion is possible. However,
not all standard ST constructs can be converted to LAD/FBD. Please keep in mind that after
a conversion from ST to LAD/FBD you cannot reverse the safety program code back to ST.
● In antivalent mode wiring, the NO channel is always connected to the lower channel
(the channel that delivers an aggregated 2-channel safety value to the safety CPU). Is
there any specific reason for this?
This behavior is as designed to avoid any faults during antivalent sensor wiring and potential
misinterpretation of which channel delivers an aggregated 2-channel safety value.
● While using our safety and non-safety I/Os with 3rd party safety (F-Host) and non-
safety CPU, will safety and non-safety I/O diagnostic messages be available in the
diagnostic buffer of those 3rd party safety (F-Host) and non-safety CPUs?
All diagnostic messages from safety and non-safety I/Os are non-safe data which is col-
lected by non-safety CPU (also 3
safety I/Os are currently available in AC500 diagnostic message format and can be read
and put in the diagnostic buffer of 3
standard PROFINET diagnosis.
● Who could certify a safety program?
All international and national accredited certification bodies like TÜV, EXIDA, UL, etc. (some
of them operating around the world) could certify a safety program.
30
rd
party one). All diagnostic messages from safety and non-
rd party non-safety CPU by invoking special FBs or using
3ADR025091M0208, 12, en_US 2020/06/19