Siemens SIMATIC ET 200SP Manual page 28

Connection
4.1 Terminal assignment
Use with dark BaseUnit Type C1
If you are using a combination of CM AS-i Master ST and F-CM AS-i Safety ST on the same
AS-i network, use the dark BaseUnit. In this case, plug the CM AS-i Master ST module into a
light BaseUnit Type C0. Next to it on the right, plug the F-CM AS-i Safety ST module into a
dark BaseUnit Type C1.
In this case, connect the AS-i network to the light BaseUnit. The dark BaseUnit does not
have to be connected to the AS-i network because the connection is made automatically via
the BaseUnit group.
In contrast to other BaseUnit types, for the BaseUnits Type C0 and Type C1, the P1 and P2
busbars of the BaseUnit are electrically isolated from the front panel connecting terminals
1L/2L (ASI+) and 1N/2N (ASI-). An electrical connection is made in each case via the
plugged-in CM AS-i Master ST module or F-CM AS-i Safety ST module.
The AS-i voltage connected to the light BaseUnit Type C0 is applied through the plugged
CM AS-i Master ST module to the busbars. The busbars of the BaseUnit group are
connected-through. The F-CM AS-i Safety ST module is supplied with AS-i voltage via the
busbars of the dark BaseUnit Type C1. It is not permitted to continue the AS-i voltage from
the front panel connecting terminals 1L/2L (ASI+) and 1N/2N (ASI-) of the dark BaseUnit
because this type of current draw can cause an overload in the modules.
If you want to maintain the voltage supply of the F-CM AS-i Safety ST module when the
CM AS-i Master ST module is unplugged from the light BaseUnit, you can wire an external
connection of the connecting terminals 1L/2L (ASI+) and 1N/2N (ASI-) between the light
BaseUnit Type C0 and the dark BaseUnit Type C1.
Grouping of a light BaseUnit Type C0 with several dark BaseUnits Type C1
The use of a single F-CM AS-i Safety ST module on an AS-i network is generally sufficient. If
several F-CM AS-i Safety ST modules are being used on an AS-i network by means of
series connected dark BaseUnits Type C1, you must wire an external connection of the
connecting terminals 1L/2L (ASI+) and 1N/2N (ASI-) between the light BaseUnit Type C0
and a dark BaseUnit Type C1. This will prevent an overload of the modules. A current draw
from the dark BaseUnit is not allowed. Additional information about this can be found in "Use
with dark BaseUnit Type C1".
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Fail-safe Module F‑CM AS‑i Safety ST (3RK7136‑6SC00‑0BC1)
Manual, 03/2017, A5E03957059020A/RS-AB/002