fmilhaupt, thank you for the answer and info. Technology...you got to love it...maybe.
The DT400 was designed before anyone had pushed to have functions above F12, so the short answer is that you can't make it access functions above F12.You're not at a complete dead-end, however. You can have Digitrax convert your DT400 to a DT402, which can access functions up to F28, and has a few other additional features. The instructions for how you can have this done are found on the Digitrax web site's Tech Support page, specifically at https://www.digitrax.com/support/conversions/dt402/
-Fritz Milhaupt, Publications Editor, Pere Marquette Historical Society, Inc.http://www.pmhistsoc.org
I got a new Scale Trains locomotive. I have Digitrax DB150 and a DT400 throttle. The new locomotive has "F" functions up to F20, how do I get to "F" functions on my DT400 past F12? I looked at the manual and couldn't head or tails out of it.