Probably the top 2 options are Digitrax Loconet and C/MRI. There are tons of third party options for detectors and signal controllers that interface to Loconet, and you cna set up and run Loconet as the control bus for all this without even using a single Digitrax product and other thant he block detectors there would be no interface to the track, so your trains would still all run on DC. ANd even the block detectors don;t need electrical connection if you use photosensors instead of current detection. There's a healthy DIY community around Loconet with multiple people offering circuits to use, in addition to multiple commercial ready to go options.
--Randy
Modeling the Reading Railroad in the 1950's
Visit my web site at www.readingeastpenn.com for construction updates, DCC Info, and more.
It's not DCC, but Bruce Chubb's C/MRI will easily handle detection, signaling, and route control on a DC layout:
http://www.jlcenterprises.net/
And if you find that C/MRI's emphasis on "roll your own" BASIC software isn't your cup of tea, JMRI interfaces with C/MRI quite well and is quite powerful:
http://jmri.org/
Sorry up front if this is covered somewhere but It wasn't immediately obvious as I searched.
I'm working on a Z scale plan and though some engines are able to be converted to DCC, some of the ones I have and will still want to use are just too small or awkward. Still others are just too special for me to want to "hack up" for things like motor/frame isolation, to make it work. I'm modeling Germany in 1939 and have a number of older Marklin engines.
But I like the idea of route planning and switch and signal control with DCC. Regardless of how the track is wired and the engines controlled I think it could be a good direction to go and even prepare for a possible future change to include the track/engine in DCC.
Basic stationary controls seems fairly straight forward, admittedly waisting a lot of what's on a handheld controller but more in line with computer interfacing.
What's giving me trouble is how to do train/car location and block detection. DC current draw detection and (unknown) interfacing into the DCC/computer or is there a DCC block detection device/method that's compatible with DC train control?
Any help?