Here is the thing....I don't believe the serial commands that worked for the HP-1 will work with the HP-2.
There was some discussion about adding them to the HP-2 and I believe it was on Paul's list at some point but I don't think it ever actually happened.
I could be wrong as it has been several years ago but that is what I remember from being a beta tester for the units.
A few commands might work but I don't think ALL of them were added. Hence the reason why HPe-RC was never updated to support the HP-2.
Hey if you can get them all to work cool beans. But I do remember adding additional commands to the HP-2 was on Paul's "To do list".