freeware versions 
The limitations of freeware version:
x2ipi72 - 2000 readings, 81 electrodes, no IP data;
x2ipi48 - 500 reading, 48 electrodes, IP data support 
full version (Sign)  / 2-10-2017 For Guardant Sign dongle ( MS Windows XP to Windows 10 ), all drivers are included
full version (Stealth II) / 2-10-2017
For Guardant Stealth II dongle (public code FS0K10T)
 Manual for x2ipi /18-10-2017
     Hardware key (dongle) software drivers and diagnostics
guardant.comGuardant drivers page 
GrdDiag.exeDongle diagnostics
  Sequences examples (Wenner-Schlumber, Dipole-Dipole, Pole-dipole arrays)
 Syscal-Pro Switch 72[.txt] format, see details
 Syscal-Pro Switch 48[.txt] format, see details
 Terrametet LS (4x21)[.xml] format, see details

Supported by IRIS Instruments