The CP 243-2 is the AS-Interface master connection for the 22x CPUs of the SIMATIC S7-200. By means of connection to AS-Interface, the number of inputs and outputs available for the S7-200 is greatly increased (max. 248 DI / 186 DO on the AS-Interface per CP).

Analog values (per CP a maximum of 31 standard analog slaves with up to 4 channels each) also become available on the AS-Interface for the S7-200 thanks to the integrated analog value processing. Up to two CP 243-2's can be operated on the S7-200 simultaneously.