Siemens SINAMICS S120 Device Manual page 402

Options
8.20 K90, Control Unit CU320-2 DP
The customer terminal block- X55 is installed in the cabinet together with the CU320-2
Control Unit. The digital inputs/outputs of the Control Unit can be used via terminal blocks -
X55-X122 and -X55-X132.
Note
Internally wired interfaces
Interfaces -X1, -X2, -X3, and -X4 are wired within the cabinet and are not available for
customer connections!
If the customer terminal block is ever replaced, connectors -X1 and -X2 must not be
interchanged! Otherwise, "Safe Torque Off" and "Safe Stop 1" will malfunction!
Note
Customer terminal block is standard
The customer terminal block is a standard component in the cabinet with the Motor Module
Cabinet Module (chassis format). The digital inputs/outputs of the CU320-2 Control Unit on
terminal blocks -X55-X122 and -X55-X132 can only be used in conjunction with a Control
Unit.
Note
Power supply for the digital inputs
The two groups of digital inputs (DI0 to DI3, DI16 and DI17 or DI4 ... DI7, DI20 and DI21)
each have a common reference potential per group (reference ground M1 or M2). To close
the circuit when the internal 24 V supply is used, the reference grounds M1 / M2 are
connected to internal ground (M).
If power is supplied from an external source, the jumper between ground M1 and M or M2
and M must be removed in order to avoid potential looping. The external ground must then
be connected to terminals M1 or M2.
402
Cabinet Modules NEMA
Manual, 04/2014, A5E03586450A