Front connector module with flat round cable connection for digital 16 I/O modules of the S7-300, power supply via spring terminals The front connector module for SIMATIC S7-300 with spring terminals for potential supply, for connecting 2x16-pin connecting cables is a modified front connector for connection to a digital I/O module. This is plugged into the module to be wired instead of the front connector. The connecting cables are plugged in here and connected to the connection module. This modified front connector module is part of the fully modular connection of SIMATIC TOP connect for the fastest and safest system cabling. In addition to low wiring effort, sources of error in the cabling can be significantly reduced. Sensors and actuators from the periphery are connected to the connection modules of SIMATIC TOP connect and connected to the SIMATIC S7-300 via a connecting cable and front connector module.