Siemens TI305-03DM Serial Communication Module

Siemens TI305-03DM Data Communications Unit (DCU) for the TI 305 series PLCs provides a dedicated RS-232 serial interface for point-to-point connections to external hosts, such as programming PCs using TI software. The module includes a single RS-232 port and must be used in a point-to-point configuration (the 305-02DM variant offers RS-422 and multi-drop capability). Baud-rate and internal-function settings are configured via DIP switches on the module; 9600 baud is the default when DIP switch SW4 is OFF. This DCU enables direct serial communication between the TI 305 PLC and a host, and is commonly used with TI's TISOFT or equivalent serial programming utilities. In the TI305 family, the DCU is the standard interface to external devices, supporting straightforward host-to-PLC serial links via the 305-03DM's RS-232 port.