Siemens SIRIUS 3RK3 Equipment Manual page 212

Operation
6.5 Connecting to the AS-i master via AS-Interface
Incorrect code sequences
Note
Important requirement
During the teaching process the contacts of the safety-related AS‑i input slaves must be closed
at least once to allow the code sequences to be retaught.
If the contacts are not closed, calculation continues in the logic diagram with the substitute
value "0." The current status of the AS-i slaves is displayed in the "Target system" > "Learn ASIsafe
code tables" dialog box in Safety ES.
Safety-related AS‑i input slaves and safety-related AS‑i outputs can be distinguished using the IO
code. However, as this cannot be monitored on the AS‑i bus by the monitor, the MSS 3RK3 with
AS-i interface analyzes the incoming code sequences and recognizes the different safety-related
slave types based on the identified code sequence type. The MSS 3RK3 interprets the data of the
safety-related AS‑i input slaves as code sequences based on its configuring and the detected ID
code. If a comparison with the taught code sequence fails, for example, due to the replacement
of an input slave with another type, the safety-related AS-i slave in question is calculated in the
interconnection logic using the substitute value "0."
Note
Incorrect code sequence table during startup
During startup, the MSS 3RK3 with AS-i interface checks the consistency of the code sequence
tables stored in the device. If any of the code sequences are shown to be invalid, all the stored
code sequences are rejected and all safety-related AS‑i input slaves on the bus have to be
retaught. The code sequence table might be invalid, for example, if the voltage supply of the
device failed during storage of the code sequence table.
Error during teaching of code sequences
If there are errors in a received code sequence or the code sequence table is not clear, the device
remains in teach phase until it is successful. Code sequence errors are indicated by a red AS-i LED
that lights up and can be more precisely defined with the Safety ES software.
Note
Incorrect code sequences and an unclear code sequence table are not interpreted as a
configuration error and do not generate a group error (SF).
Double code sequences on the AS-i bus
If the code sequence that a newly inserted safety-related AS‑i slave outputs is identical to an
existing code sequence, the substitute value "0" is used for both slaves.
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SIRIUS 3RK3 Modular Safety System
Equipment Manual, 07/2020, NEB926253002000/RS-AC/006