Siemens SIRIUS 3RK3 - Page 372

Probability of a dangerous failure per hour (PFH
D
)
2.8 x 10
-9
1/h (without use of AS-i)
3.8 x 10
-9
1/h (with use of AS-i)
Probability of a dangerous failure on demand (PFD)
1.7 x 10
-4
Characteristic values for cables
Max. permissible cable resistance 100 Ω
Max. permissible cable length from device to sensor
(for CU 1.5 mm
2
and 150 nF/km)
1000 m
(i.e., max. total cable length of 2000 m)
Max. permissible cable capacitance 330 nF
Dark period semiconductor outputs < 1 ms
AS-Interface data
AS-i voltage 18.5 V DC ... 31.6 V DC
AS-i power consumption < 45 mA
AS‑i bus load like A/B slave
AS-i slave pro󹪝les (simulated slaves)
• S-7 F.F (4I/4O): standard slave (max. 4)
• S-7 A.E (4I/3O): AB slave (max. 4)
• S-6 B.D: safety-related output slave for controlling a safety-related
AS-i output (maximum of 8)
• S-0 B.F: Safety-related input slave for AS-i link (maximum of 8)
• S-7 5.5: (standard CTT2 + 2I/2O) CTT2 slave for transmission of
diagnostics information (maximum of 1)
Number of devices per AS-Interface line In the maximum con󹪝guration of the AS-Interface network in which
31 standard addresses are used, you can install up to four additional
safety monitors without addresses.
If fewer than 31 standard addresses are used, a further monitor can
be installed for each unused standard address. If you install additional
nodes without an address (e.g., ground fault monitoring modules),
this reduces the number of safety monitors that can be installed ac‐
cordingly. When repeaters are used, this de󹪝nition applies to each
segment.
1)
The number of function elements that can be processed by one MSS 3RK3 depends on the type of function elements.
2)
Protective separation, reinforced insulation 4 kV between input circuit and output contact current paths.
3)
Time from instant an output is switched o󹪜 to the instant the output reaches a state that permits it to be switched on again.
4)
The mechanical durability may be reduced, depending on the contact load.
Technical data
8.5 3RK3 ASIsafe basic central unit
SIRIUS 3RK3 Modular Safety System
372 Equipment Manual, 07/2020, NEB926253002000/RS-AC/006