The MD3 modem offers all the advantages of the SIMATIC S7-300 design:

• Compact construction;
  double standard width of SIMATIC S7-300 SM modules
• RJ12 socket for connecting the modem via the supplied connecting cable to the telephone jack or the dedicated line
• 9-pin Sub-D connector with an RS232 interface for connecting the modem to the RS232/RS485 interface of the TIM
• 9-pin Sub-D connector with an RS485 interface for connecting the modem to the RS232/RS485 interface of the TIM
• 4-pin plug-in terminal strip for connection of the 24 V DC external supply voltage
• Front-panel LEDs indicating TXD, RXD, DTR, RTS/ONL, CTS/RI and DCD
• Easy installation;
  the modem is mounted on an S7-300 mounting rail; alternatively, it can be mounted on a 35mm standard rail using the adapter 6NH7760-0AA, available separately.
• The modem can be operated without a fan.