The system modules are connected to the CPU on the left-hand side via a multi-pin connector. Internally they are connected via PCI Express®. For the CX20xx family, up to four modules can be connected in any order. One module can be connected to CX52x0, CX53x0 or CX56x0.

The CX2500-0061 Power over Ethernet module supports devices with PoE class 0, 1, 2, 3 and 4 in accordance with the PoE standard IEEE 802.3af-2003. The maximum PoE power output is 15.4 W. The PoE supply voltage is generated internally, no external power supply is necessary. In the case of an overload of the CX2500-0061, the PoE supply shuts down for two seconds, then restarts. The diagnostic LEDs PWR, PoE, PM1 and PM2 provide information about the type of PoE supply (mode A or B) as well as about the PoE class reported by the powered device.