Siemens SIRIUS 3RK3 - Simulated AS-I Slaves

no restrictions, that is, the groups may contain the same AS-i slaves, or only subsets, or no
common AS-i slaves. The individual 3RK3 central units with AS-i interface can also monitor one
another and communicate with one another.
Note
Exchange of up to 12 safety-related signals
The MSS 3RK3 with AS‑i interface can simulate multiple safety-related AS-i slaves on the AS-i bus.
These can be either safety-related input slaves for controlling an F‑link or safety monitors, or
safety-related output slaves for controlling safety-related AS‑i outputs or a combination of the
two.
The number of simulated safety-related AS-i slaves depends on the type of central unit:
• The MSS 3RK3 ASIsafe basic can simulate up to 8 safety-related AS‑i slaves.
• The MSS 3RK3 ASIsafe extended can simulate up to 10 safety-related AS‑i slaves.
• The MSS 3RK3 Advanced can simulate up to 12 safety-related AS‑i slaves.
6.5.7.3 Simulated AS-i slaves
AS-i slave function - simulated slaves
Simulated slaves are required for transmitting bit information to other devices on the AS‑i bus,
for example, to the safety monitor or to an additional MSS 3RK3 unit with AS-i interface. In
principle, they have the same properties as real slaves, in particular regarding their AS‑i address,
process data exchange, terminal identi󹪝ers, and equipment identi󹪝er (BMK).
The following must be noted for simulated slaves:
• The MSS 3RK3 does not monitor its own simulated AS‑i slaves with its monitoring function.
Where values from output terminals of simulated slaves are used again as an input in the
logic, the input value is not derived using the monitor function but the value of the output
terminal is used. This means that the value will be available to the safety logic in the next
processing cycle of the MSS 3RK3. There are no asynchronous dependencies between the
cycle time of the MSS 3RK3 and the cycle time of the AS-i bus.
• Simulated AS‑i slaves are also visible on the AS‑i bus outside safety mode and test mode.
However, only zeros are returned as output values in con󹪝guration mode. All received input
values are ignored.
One exception to this is the simulated AS‑i slave with CTT2 pro󹪝le, as this is used for device
diagnostics of the MSS 3RK3 and therefore supplies correct diagnostics data using the CTT2
protocol in con󹪝guration mode, too.
You will 󹪝nd additional information in Chapter "Diagnosis using AS-Interface (CTT2 protocol)
(Page 298)."
• Downloading a new con󹪝guration
No AS‑i slaves are simulated while a new con󹪝guration is being downloaded. Therefore no
simulated slaves are visible. Only after the correctness of the con󹪝guration has been
evaluated are the AS‑i slaves in the new con󹪝guration simulated on the bus again.
Operation
6.5 Connecting to the AS-i master via AS-Interface
SIRIUS 3RK3 Modular Safety System
216 Equipment Manual, 07/2020, NEB926253002000/RS-AC/006