LCC II - How It Works - Physical
This is the second in a series of posts on the NMRA's new Layout Command Control (LCC) standards. The first post covered the reasons why a control bus, and specifically LCC, were important, as well as providing a fairly high-level view of how LCC works. Today we'll get into some very specific details regarding the physical aspects of the network, specifically the CAN Bus wiring and usage. Next time, I'll cover the actual messaging on the network (i.e., what you can do with it).
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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.
Read More...
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.
Read More...
