Need help setting up sweep function for signal generator
Although I still wasn't able to find a manual online, in an ad for one of the products for the similar SG100x series (same as mine w/o an ADC or second TTL port), it mentions the sweep function going from frequency f1 to f2.  As mentioned in my question, I couldn't find any direct way to set the starting and ending frequencies, but seeing them labelled f1 and f2 got me thinking.

There is a Save function which saves the current parameter setup to one of 10 "slots", numbered 0 through 9.  Sure enough, setting up the starting frequency and saving the current setup as slot 1 (skipping slot 0), and then setting up the ending frequency and saving the setup as slot 2, and then setting the Sweep function to Run causes it to use these two frequencies as the start and end point.  All the the other parameters such as the signal type (square/triangle/square, sweep duration, etc. are taken from the current setup when Run is selected. 

Rather obscure user interface.

Update

I was finally able to find the manual for my specific model online here.