One of three power supply modules can be selected for CX1030 systems. The power supply of all other system components is ensured via the internal PC/104 bus; no separate supply lines are required. However, the CX1100 components offer further important characteristics that go beyond a pure power supply: an integrated NOVRAM enables the fail-safe storage of process data, an LC display with two lines of 16 characters each is used for displaying system and user messages. Local I/O signals are connected via the CX1100-0012 power supply variant, to which all Beckhoff Bus Terminals (KLxxxx) can be connected, or via CX1100-0013, which in addition to the Bus Terminals enables the connection of Extension Box IExxxx type Beckhoff Fieldbus Box modules. The option to connect Bus Terminals or Fieldbus Box modules creates a control system with a very variable, expandable I/O level with large signal variety. The I/O data are stored in a DPRAM, which is accessible by the CPU via the system bus. All EtherCAT Terminals (ELxxxx) can be connected via the CX1100-0014 power supply unit. With the CX1100-0014 the I/O data are stored directly in the main memory of the CPU; a DPRAM is no longer required. The power supplies of the CX system can be changed in the field. The CX1100-001x power supply units are electronically identical to the CX1100-000x power supply units, but with an internal heat sink and additional ventilation apertures. Although they are intended for use with the CX1030, these power supply units can also be used with the CX1020 and CX1010 in order to enable alternative mounting directions (see documentation).