The compact switch module CSM 377 features all the advantages of the SIMATIC S7-300 design:

• Compact construction;
  the rugged plastic enclosure features the following on the front panel:
  • 4 x RJ45 ports for the connection to Industrial Ethernet (retaining collar)
  • 1 x 2-pin pluggable terminal strip for the connection of the external 24 VDC power supply
  • LEDs for diagnostics and for status display of the Industrial Ethernet ports
• 10/100BaseTX;
  automatic detection of the data rate with autosensing and autocrossover function for the connection of IE FC cables by means of IE FC RJ45 Plug 180 up to 100 m
• Simple mounting;
  the CSM 377 switch module is mounted on the mounting rail of the S7-300. As it has no connection to the backplane bus of the S7-300 or ET 200M, it must either be inserted at the beginning (first module to the left of the CPU) or at the end (last module on far right) of the S7-300 station. The connection to the CPU of the S7-300 is either by means of an Industrial Ethernet cable or an Industrial Ethernet twisted pair cord.
• Three further Industrial Ethernet interfaces (TP ports) are available for the connection of additional Ethernet nodes such as HMI panels or ET200
• The CSM 377 can be operated without a fan and no backup battery is necessary
• The module can be replaced without a programming device