LCC I - Layout Command Control

Three years ago, in 2012, the NMRA published their first standard related to a layout control bus, at the time known as NMRAnet. This was standard S-9.7.1 NMRAnet: CAN Physical Layer, which defined the electrical characteristics of the bus (e.g., details of the wire, connectors, bit rate, and voltage levels). Several companies were producing useful circuit boards based on the standard, although their functioning depended on capabilities not adopted at that time.

This standard, and the not-yet-adopted parts used to make the first implementations, were based on something called OpenLCB, which stands for Open Local Control Bus (not "Layout Control Bus"). Open LCB was one of several competing proposals for NMRAnet. The OpenLCB team demonstrated how this would work at the 2010 NMRA convention, and has a page of videos and other information from then. Over the subsequent two years it came out on top as the solution of choice. However, some of the potential demonstrated there does not seem to be fully fleshed-out in even the current standards. We're not done with the development of LCC by any means.

But we have had significant progress this year. Back in February the NMRA adopted 21 additional documents, 10 more Standards and 11 clarifying Technical Notes. They also renumbered them slightly, and changed the name to Layout Command Control, or LCC. These were formally adopted with a six-month comment period that ended on September first. Updates based on those comments are still possible, so the standards aren't quite done yet, but they're probably very close to their final form.

Decoder Wars II - Lightboards

Comparing decoders for cab cars is actually relatively simple. These don’t need to do very much, so it’s really about checking basic functionality. I’ve laid out the full testing details on my Decoder Comparison Testing page, and here I’m going to summarize the findings for the capabilities of interest to me.

Decoder Wars I

Edit: see the comments for some additional notes; also, I’ve edited the text to correct some errors, but those edits are marked.

A long time ago, in a distant land, titans met to do battle...no, wait, I mean recently, on my kitchen table, I started testing DCC motor decoders for N-scale EMUs. And as with most wars, after it started I began wondering why on earth I’d thought it was a good idea. Still, I have reasons for this, and the result is important: the winning candidate will go in my (so far) 27 trains that don’t support Kato’s plug-in decoders, and some have two motor cars, so it’s closer to 30 decoders.

DCC Voltage and Cab Lights

’m turning my attention to the cab car decoder install now, and a recent discussion with Don along with a question from a reader had me thinking about potential problems with DCC conversion of N-scale EMU cars with cab lighting. And the one that really worried me was overvoltage from high DCC track voltages, and its harmful (fatal) effect on LEDs. DCC decoders essentially pass track voltage (minus a small bit) through to their function outputs.

November 2012 Status

November, as you may have noticed from recent posts, went largely to laying the groundwork for installing wire-in DCC decoders, and a bit of testing of same. After a few delays, most of what I was waiting for finally arrived, although a few things are still backordered. In particular, the six-pin NEM651-compatible plugs and sockets mentioned in the comments last time have arrived. For the curious, the parts list has been added to my page on DCC Decoders. Read More...