Besides its use for conventional voice and data communication, TETRA technology has potentially widespread industrial applications in telemetry and telecontrol networks, such as in the utility industries, and in machine-to-machine (M2M) communications.

A versatile TETRA terminal which supports all the common data protocols (and many more) used in these applications is the TMO-100 from the German manufacturer Funk-Electronic Piciorgros. This has recently passed TETRA interoperability testing with Rohill infrastructure, in tests covering all types of SDS, packet data, multi-slot packet data, authentication, encryption, secondary control channel and other functions.

Supporting serial protocols such as Modbus, PakBus, Sinaut and others, the TETRA TMO-100 has an integrated LZ77 data compression mechanism that automatically compresses/decompresses all data received or sent through its serial ports. In addition to serial asynchronous protocols, the unit can also process UDP and TCP-data, operating as a wireless router.

Data access

After the device is switched on, a PPP connection to the Tetra infrastructure is automatically established and the unit receives an IP network address from the Tetra switch. From that moment, the TMO-100 becomes a transparent IP communication device with NAT, port forwarding and port translation, performing as a fully-featured TETRA router. A user can simply connect his computer or other device to the ethernet port and, after setting up the local IP address, he will be able to communicate with other devices or a Scada (Supervisory Control and Data Acquisition) server within the TETRA network (and, if enabled, beyond that). 

For applications that need embedded digital or analogue inputs and outputs (I/O), the TMO-100 can be delivered with an optional I/O-board featuring 16 digital inputs, eight (or 16) digital outputs and four analogue inputs (12 bit resolution). The device is equipped with eight event counters and eight timer counters. All inputs and outputs are isolated.

Voice contact

A further feature of the TMO-100 is the ability to set up a voice connection by plugging in a remote speaker-microphone handset. When the PTT (push to talk) button on the handset is pressed, the modem disconnects all data links and automatically switches into voice mode. A voice call is then set up to a preset destination. After the conversation, data communication will be restarted by the device automatically.

To support the TMO-100, Picorgros offers graphical software for Windows and Mac computers which can be used to design special applications. Such applications can implement M2M communications with operations such as processing inputs and outputs with digital and analogue functions, sending dynamic text messages to Tetra handportable terminals or to SCADA servers, calculating coordinates using an external GPS, or sending emails.

• www.tetramodem.com