DSM Pro vs DSM2
 

Are DSM Pro and DSM2 the same thing? If not, what's the difference in DSM, DSM Pro and DSM2? Thanks.

No, DSM Pro & DSM2 are different. Each step you list has faster response in that order.

As far as I know the DSM & DSM Pro are fully interchangeable. Both the Pro transmitter and receiver improves speed.

A DSM2 receiver requires a DSM2 transmitter. (3100 & 3520 receivers)
A DSM2 transmitter will work with any receiver, DSM, Pro, or 2. (but gets faster with higher spec receiver)

In other words the DSM2 transmitter is backwards compatible, the receivers are not.

The DX3R is DSM2 and is capable of the fastest response. (5.5ms frame rate with digital servos and a DSM2 receiver)
The early DX3S was DSM, later version is DSM2, but not quite as fast as a 3R. (can’t do the 5.5 frame rate)

Best as I understand anyway.

Software DSMPro
 

Do you have the DSMPro Software?