The G120 is the updated version of the G100, boasting an improved feature set. 

It is capable, as per the G100 to be used as an Iridium Hybrid device, however the implementation is slightly different. 


The Iridium satellite constellation provides L-band voice and data coverage to devices utilising an Iridium modem all over the earth's surface. So a G120 Iridium hybrid device can provide location updates when out of cellular coverage.


The G100 used a Flexi card slot so that an Iridium modem could be fitted to the device. This is not the case with the G120. 


The components needed for out of coverage Iridium tracking with a G120 are:


  1. G120 Device (standard unit - supplied by DM)
  2. Iridium Edge Module - not supplied by DM, can be sourced via other suppliers
  3. G120 Iridium wiring harness - (optional but recommended, supplied by DM)


This has the benefit that res


The Iridium Edge Module. 

The Iridium Edge module is a self contained Iridium modem + antenna, which can be mounted in the location an Iridium antenna would be traditionally mounted. From there it connects via a harness to the G120. 


The Iridium Edge is simply the pictured box, with a cable coming out which is terminated with a M12-8 connector on the end.


It requires a 9-32V power source. 


The DM G120 Iridium Wiring Harness

The Iridium Edge module communicates with the G120 via the G120's RS232 interface. 

The RS232 interface wires are available on the standard G120 harness - so partners can wire their own connections if desired. 


The DM Iridium harness simply terminates the following wires of the standard G120 harness with a M12-8 connector, so it is plug and play with the Edge Module


  • Power on Iridium edge is fed back along cable and joined to G120 power cable (pin 24)
  • RS232 RX (pin 22 on G120)
  • RS232 TX (pin 21 on G120)
  • GND (taken back to G120 GND)
  • SW GND (pin 11 on G120) - controls on/off of Edge


Note the input voltage range of the G120 is 8-45V DC

The diagram below states 9-32V, since this is the range for the Edge and this must be adhered to (shared power rail)




Building your own Harness

If you wish to build up your own harness, the necessary connections are given here:

G120 Iridium Harness