I’ve been a Dexcom user for approximately four and a half years. Initially I got the Dexcom Seven that had to be calibrated using a cable connected to a LifeScan OneTouch Ultra meter. It did not work with any other meter because of FDA restrictions. It shipped with DM2 software for the computer.
Once the FDA decided you could calibrate with other meters, there was a software update to upgrade the receiver making the cable (for those who used the Ultra meter) optional and putting in place the existing screens to enter your readings.
Then Dexcom came out with the Seven Plus. That was a completely different product that had upgraded software with better algorithms for accuracy. At the same time DM3 was released for the PC. For a few months when the Seven Plus came out, Dexcom offered a special upgrade price for existing customers.
There have been several versions of the PC software. Currently I’m running DM3 version 22.214.171.124. My Dexcom Seven Plus receiver is running version 126.96.36.199. These should be the latest versions since I just had my unit replaced a couple of months ago.
Hope this answers your question.