Siemens LOGO! Series Manual page 52

LOGO! installation and wiring
2.3 Wiring LOGO!
Sensor connections
To connect sensors to LOGO! :
LOGO! 12/24.... and LOGO! 24...
LOGO! 230....
Current safety regulations (VDE 0110, ... and IEC 61131-2, ... as well as cULus) do not
permit the connection of different phases to an AC input group (I1 to I4 or I5 to I8) or to the
inputs of a digital module.
52
WARNING
The inputs of these devices are not isolated
and therefore require a common reference
potential (chassis ground).
With LOGO! 12/24RCE/RC/RCo, LOGO!
24/24o and LOGO! 24C/24Co modules, you
can tap analog signals between the supply
voltage and chassis ground (* = series
resistor (6.6 kΩ) at 24 V DC).
The inputs of these devices are arranged in
two groups, each consisting of four inputs.
Different phases are only possible between
blocks, but not within the blocks.
Manual, 04/2011, A5E03556174-01
LOGO!