The Service Manual says to measure the frequency of the timing belt using the DDS. This is crazy, I've never heard of measuring the frequency, precise..
Anyways, most of us don't have this to check it. How do you measure the tension and what do you set it at?
You can read frequency with the software. The other methods such as belt twist and the allen key do not apply to the DS1100 motor as the rollers are asymetrical in position.