Well this weekend saw the start of the conversion from Digitrax Simplex to the Digitrax Duplex on The Little Rock.
A few years ago one of my two original DT400r's started showing some weird actions.
The screen would flash back and forth between the track power voltage and the series ID of the throttle along with a series of Hex numbers and never quit doing this.

Example:

Pwr 11.1V
0000 0o 0301

to

DT300 v1D
eO123o6789

then back to 

Pwr 11.1V
0000 0o 0301

After doing some research I found it was due to some capacitors in the DT300 and DT400 series throttles. I found out you could send them and for $25 and Digi would repair them.

Chatting with my DCC Guru about this he mentioned that if I send them in for repair I might as well have the upgraded to the Duplex system as they were planning to discontinue the Simplex system soon. So I followed his lead and bought a UR92 from him and sent the bad DT400r's and a UT4r so when the time came to send in the rest of my throttles, I wouldn't be left with no throttles to run the layout.

Well this weekend I gathered up those two throttles and the UR92. I installed the UR92 right where the UR91 was installed and went through the setup procedure with the DT402d and UT4d and within a few minutes I was running trains under the Duplex system.
The nicest thing so far is not having to always plug the throttles into a UP5 panel to acquire a loco or consist.

Now I need to get the paperwork in order for the repairs/upgrades of my other throttles and get them sent in.