Siemens SINAMICS S120 Manual page 448

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8.22 K95, Control Unit CU320-2 PN
Note
Customer terminal block as standard
The customer terminal block is a standard component in the cabinet for 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.
446
Cabinet Modules
Manual, 03/2013, A5E03263538A