PS3 and DCC

Hi Sam,

I've been running MTH PS3 engines on DCC since their first HO engine came out in 2006.  As Dave alluded, the speed table they come with out of the box is the same as under DCS.  DCC allows you you to run engines with 14, 28, or 128 speed steps.  Virtually every DCC system manufactured in the last 10+ years supports 128 throttle steps, so almost all DCC users run at 128.  PS3 engines (HO or O) run on 128 DCC speed steps use the same linear speed map as DCS: 1 step = 1 smph.  Currently, MTH is the only manufacturer that has adopted any kind of a consistent speed map in DCC.  What we take for granted in DCS, and now Legacy as well, was simply unheard of in DCC. 

In HO, "consisting" (aka lash-ups) is very common because most engines don't have traction tires.  Virtually all decoders are manufactured by a different company than the train models.  For instance, Athearn uses SoundTraxx Tsunami decoders in their Genesis series engines.  It's also still common in DCC for people to purchase and engine without a decoder and install their own.  As a result, the DCC market doesn't expect their engines to have a consistent speed maps out of the box.  DCC decoder manufacturers responded by giving the end user a couple ways of adjusting speed.  The end user can spend hours clocking the speed of the engine at each speed step and tweaking the CV's so that two or more engines will match each other.  It's a very tedious process and not terribly accurate compared to DCS.  However, some DCC "power users" used this technique to establish their own custom speed maps.  Originally, when MTH released their PS3 engines they ran in DCC with the stock DCS speed map and that was it.  At lot of those DCC "power users" had a cow because they could spend hours reprogramming the engines to their custom speed curves.  It took a while, but MTH gave the power users what they wanted.   The long list of control variables (CV's) in DCC mode are used to create a custom speed curve.  Frankly, it's a lot of work to end up with a less consistent user experience.

Most of the other CV's are related to "function mapping."  Most of the features on a DCS remote (headlight, bell, whistle, volume, softkeys) are handled in DCC with "function" buttons.  Until the mid 2000's, DCC was limited to 13 functions (0-12).  Today, most sound decoders and DCC systems support 29 functions (0-28).  However, there are still a lot of DCC systems in use that can't access F13-28.  The function mapping CV's allow the end user to "map" any of the available locomotive functions (well over 29 options with PS3) to the function address of your choice.  It's a good work around for people with older equipment who would rather by a new engine than replace their DCC system hardware.  Like speed mapping, MTH didn't originally include function mapping in HO PS3 decoders.  It was pretty major oversight which has since been corrected.  To someone accustom to DCS, it feels more like hacky patch than a feature.

The other feature MTH added to their DCC support is called "advanced consisting."  Many DCC systems support two different forms of "consists" (lash-ups).  The first form of consisting is called a "brute force," "old style," or "universal" consist depending on the manufacturer.  In this form, the DCC system sends separate commands to each locomotive in the consist and is responsible for keeping track of which engine is in the lead, which is in the tail, and which way each is pointed.  It works well, but if you're running a large layout it reveals one of the major technological short comings of DCC.  DCC has very limited communications bandwidth.  Running 8 or 10 engines at once will cause communications problems because the commands can't be fed to the track fast enough.  That's not hard to do when A-B-B-A diesel sets are common and each engine is programmed with a unique ID.  So, the DCC developers came up with another work around called "advanced consisting."  Advanced consisting requires the decoder to store two different sets of data.  One set controls the parameters of the engine when run with its engine ID.  The other set controls the parameters when run with a separate consist ID.  This is the same approach used for lash-ups in original TMCC, where the locomotive could be programmed as either an "engine" or a "train."  In DCC, CV 29 is used to set the direction of travel and other parameters of an advanced consist.  There are some pluses and minuses to both forms of consisting, but for DCC advanced consisting is a must for larger layouts.  Again, if you're accustom to DCS, the whole CV programming process just seems archaic compared to building a lash-up in DCS.

Thanks Dave and all replies.  Was just curious if there were DCC PS3 Ogaugers, but as Dave  points out, its a lot of work for what seems to be little return.

To someone accustom to DCS, it feels more like hacky patch than a feature.

ROFLMAO!!

The neatest thing about DCC over DCS is that you can have an automated stop and go. By using a relay, you can switch in pure DC to your track, when the engine sees the DC is will come to a slow stop. When you switch it back and it sees the DCC signal it will accelerate to where it was running. 

Chuck,

The neatest thing about DCC over DCS is that you can have an automated stop and go.

You can do pretty much the same with DCS in 2 ways:

• Use a Record/Playback script
• Use PFA

The one advantage that Chuck is pointing out is with DCC you can automatically have the presence (or lack there of) of a train trigger a station stop or other events.  An external input is something that DCS is lacking...  for now.

That is right Dave, it is a real advantage having the ability to have another train trigger the passing siding etc...  It can also be unattended. Great for a display layout.  I could never get the record playback of the DCS to not creep. I mean it will not reliably repeat, it will invariably creep its stopping point along the route.