Complex sentence: Many different devices are available for connecting to the Orbcomm networks, most of them being simple RS-232 modules with an antenna and a power supply however there are more advanced ones available that have a simple programmable computer and GPS built in.
Split into simpler sentences: Many different devices are available for connecting to the Orbcomm networks, most of them being simple RS-232 modules with an antenna and a power supply. However there are more advanced devices available that have a simple programmable computer and GPS built in.