A number of optional interface modules are available for the CX9000/CX9010 Ethernet controller that can be connected to the basic module ex factory. The system interfaces cannot be retrofitted or expanded in the field. They are supplied ex factory in the specified configuration and cannot be separated from the CPU module. The power supply of the system interface modules is ensured via the internal bus. The CX90x0-N010 option connects Beckhoff Control Panels or standard monitors with DVI or VGA input via the DVI or USB interfaces. Devices such as printer, scanner, mouse, keyboard, etc. can be connected via the USB 2.0 interfaces. The CX90x0-N030 module offers two additional serial RS232 interfaces with a maximum transmission speed of 115 kbaud. Alternatively, the two serial interfaces are also available as RS422/RS485 signal types (CX90x0-N031). The CX90x0-N070 4-port USB hub extends the number of available USB 2.0 ports, whereby each port can handle a load of max. 500 mA (however, not all four at the same time). In this way, a total of six USB interfaces per CX are available to the user. If additional mass storage is required, the CX90x0-A001 extension module provides a Compact Flash interface for type I or II CF cards. Unlike other system interfaces, this module can be upgraded in the field. Cards may only be inserted or removed when the system is switched off.