The system has four components:
The Basic Packages with SW and HW to get started: GT-Position Standard with a build in sender or GT-Position Plug&Play with a battery sender.
The receivers (satellites)
The senders in more variants
The open interfaces.
You can see the components in the web-shop: GT-Position package
1) A small central which connects via USB to your computer. The central controls which trains transmit at what time and the central does all priotization. The central receives all distance information from the receivers. The central updates the PC-software very frequently. The Central is powered by the USB.
2) A sender with an ultrasound transmitter, 12 or 10 mm diameter. The sender has the same size as a normal decoder. It is build into the Loco or a wagon (with power supply) so that the transmitter is visible. The sender is powered by the rail current. The sender also has a battery variant with same size as an oversize Container. There is also a battry-variant to be build into the train. The sender is normally placed in a loco under a small opening like a ventillation gitter or so. It can sit in a chimney, under exhaution wholes on a tender, in an open window or so, as long as it gets a bit of air. On the MT (picture) it is placed in the back under the ventillation.
3) Two or more receivers positioned over and/or outside the layout. If you only need 2D plotting two receivers will do it. More receivers can be added as you expand your layout or add shadow shunting areas etc. One pair will do about 6 times 6 meter. Receivers are powered by rail current or 14-20 V DC (17V is norm). Can grow to 20+ receivers in order to cover large layouts.
4) PC-software is integrated with GT-Command in the first release. The GT-position SW takes care of installation and set-up of the HW, the plotting of the track, the track-layout build, the plotting of trains, etc.
GT-Command is doing the monitoring and the automation, and the basic core informations as to-day. If you have other control commands SW GT-Position can interface to them.