What is the difference between a module and a terminal?

The GSM module TRM-2 can be included in various applications.

For normal applications the module is included in the terminal TRM-2T which consists of the following parts:

  • TRM-2 (Triorail GSM module)
  • Housing (65 x 74 x 33 mm)
  • Antenna connection (FME)
  • Voltage supply: western with 6 pins modular plug, voltage range: 8 to 30 V
  • RS232 Interface (9-pin D-Sub): Connection to the PC,notebook etc. (RS-232C standard of the EIA and/or the V.24 standard of the CCITT)
  • SIM Card Holder (miniature SIM card 3 V, according to the guideline GSM 11.12)
  • Hand set connection (4-pin miniature western plug)
  • GSM status indication (yellow LED)

What is the difference between the TRM-2 and the TRM-1 sold in former times?

The TRM-2 is based on MC55 whereas the TRM-1 was based on the MC45. To satisfy the RoHS directive Triorail (as Siemens WM) switched to MC55. In comparison to the MC45 the MC55 has a reduce size, but the connector still is identical.


The AT command set is improved by a different implementation of the ATS0 command. A PIN protection, which was missing in the TRM-1, has been added to the ATS0 command.

Does Triorail plan the development of a 8 Watt GSM-R module?

Since Triorail is now implementing the ASCI functions in the TRM-2, the next step is to design the TRM-3 with an 8 Watt external amplifier. Please contact us if you are interested in such a realization. 

There is a input voltage range from 8 to 30 V for Triorail terminals. Is there a guaranty for continuous use of the modem within this range?

The modul TRM-2 itself works with a voltage from 3,3 to 4,8 V. The terminal TRM-2T contains tis modul, but  it works without problems in continuous use with a voltage in the range from 8 to 30V. Please have a look, that the voltage does not overrun 30 V.

What type of antenna connector is used on the TRM-1 / TRM-2 terminal?

The terminal has a FME (male) connector, normally used for GSM Phones. If you need an adapter you can take a look at our partner MC technologies, which offers a huge variety of GSM products.


Do your modems support "over the air" / SMS SIM-card update?

The OTA (over the air) SIM card update is included in our modules.

For the Triorail ASCI Module there is also a command for the verification of the update available.

How are the ASCI functions in the module TRM-2 ASCI to control?

The ASCI function in the module can be handled via AT commands.

Which AT-Command is used to reset the module?

The modem can be switched off by AT-SMSO. The wake up can be done by activating the DTR signal or the ignition pin.

Do Triorail modules support the feature "selective reject"?

Yes, our modules support this feature.

Does the TRM-2 work only in nontransparent mode or also in transparent mode?

Like the original module MC55 the TRM-2 works only in nontransparent* mode.


*In nontransparent mode a error correction protocol (RLP: radio link protocol) is used to secure the data transmission.

Do Triorail modules support roaming between GSM and GSM-R to bridge a gap in network covery?

Our devices support roaming. If your network provider has already closed roaming contracts, these features are available. Please asked your provider, whether your SIM card supports roaming.

Do Triorail terminals support GSM-R streaming over GPRS?

Data streaming via GPRS is not a problem with Triorail terminals.

Do Triorail modules support Java?

Unfortunately our modules do not support Java.

Does the TRM-2 terminal support hands free mode?

Yes, the TRM-2 supports the hands free functionality.

Does the TRM-2 terminal support voice calls?

Although the TRM-2 is normally used for data transmission, there is also the possibility to use it for voice calls.

06. August 2017

New product: Triorail Test Box “TTB-1”

This all-weather GSM-R measurement system enables automated test sequences as well as manual GSM-R...


01. March 2017

Innovation Day for medium-sized Businesses 2017

Triorail will be represented with an information stand at the Innovation Day for medium-sized...