Digital Input Expansion Module Suitable for switches and 2/3/4 wire BERO’s (proximity switches) Siemens S7-300 Digital and Analogue I/O Modules Expansion modules and accessories to support the Siemens S7-300 PLC range. Each S7-313 PLC CPU Base Unit may be expanded with up to 8 expansion modules. S7-314 CPU Base Units can accept a total of 4 expansion racks consisting of 8 expansion modules each.,All expansion modules share the following features: Compact design LED’s input signal status indication Front panel connector for actuators or sensors. Connectors can be coded according to application, thus preventing the connection of an incorrect unit No slot rules: the address of the input corresponds to the slot number Modules may be configured and the parameters set using STEP 7 Lite software Data is stored centrally. When a module is removed/replaced data is automatically sent to the new module, removing possible set up errors