Cinterion MC55iT GSM modem

The Cinterion MC55iT GSM modem is the successor of the Siemens MC35iT GSM modem. Cinterion acquired Siemens Wireless Modules from Siemens in 2008.

The MC55iT is a GSM modem with an RS232 serial port, external antenna and external power supply. It is a compact, well-built modem that is designed for unsupervised use in industrial environments.

Cinterion MC55iT specifications
Connection RS232
GSM Frequency bands 850, 900, 1800, 1900
Network protocols GSM, GPRS
Cinterion MC55iT

Cinterion MC55iT


Setting up the modem for operation with the RS232 serial port is straightforward. Just plug in the modem to the power supply, attach the external antenna and RS232 cable and insert the SIM card. The only caveat is the antenna connection, which is different from the Wavecom or Cinterion TC65T modems and needs an adapter to connect to the available antenna cable.

Optional settings

To increase the reliability of the modem, you can set the "RebootBeforeInitialization" option to "True" in the advanced properties of the GSM modem Gateway after the initial setup. This option instructs Diafaan SMS Server to send a full modem reboot command to the modem whenever a problem occurs and prevents lock ups of the modem.

Daily operation

As expected the modem worked flawless in the test period. The RS232 connection ensures that the MC55iT recovers well when the server recovers from sleep mode and the support for a full software reboot lets Diafaan SMS Server restart the modem when there is a problem with the GSM network connection.

SMS send speed

Network Vodafone
Signal quality High
Time to send 500 messages of 160 characters, delivery confirmation enabled. All messages sent to the same number (concurrent send and receive) 57 minutes 57 seconds


The Cinterion MC55iT is a very reliable GSM modem that is suitable for 24/7 operation in critical SMS operations. The external power supply and antenna makes it ideal for installation in a server room or other technical environments.