Layout Command Control

At this point, it's safe to assume that you may have heard of LCC. Layout Command Control is an emerging NMRA standard that is slowly gaining traction in the model railroad community. As an example, TCS' Universal WiFi Throttles are pioneering the bridge between existing DCC systems and LCC.

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The CS-105 from TCS is the first commercially available stand-alone LCC command station. LCC's robust command bus and future-proof considerations make it a great choice for modelers who are serious about operations and have a ton of signals passing through their command bus, including literal signal heads. LCC can keep track of all the locomotives, and accessory controllers you need to control without breaking a sweat. Below are some of the most frequently asked questions about LCC. You can find more technical information at: nmra.org/lcc

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Will LCC work with my DCC layout?

Yes, DCC and LCC complement one another. LCC does not make DCC obsolete. The LCC bus takes accessory traffic off of the DCC bus. Only locomotive control needs to remain on the rails.

 

Will LCC work on my DC layout?

Yes! Since LCC is a completely separate protocol with its own communications, it can be used with any train control method, including DC.

 

Is LCC bi-directional?

Yes. Unlike DCC decoders, LCC nodes can both send and receive data over the LCC bus. This allows detectors, turnout feedback, local fascia controls, etc., to each talk to one another. Additional features such as status reporting, intelligent configuration, initialization, and upgrades of the products are now possible. 

 

DCC (Digital Command Control), the existing NMRA standard for train control, is essentially a one-way bus that allows a single master command station to control mobile and stationary decoders over the rails. 

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Is LCC high speed?

The currently available LCC products operate an order of magnitude faster than DCC by using the automotive CAN-bus. There is plenty of room for extra traffic. LCC may also be operated over other, even faster networks, such as Ethernet or WiFi.

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LCC products from TCS, such as the UWT-100 and CS-105 feature a real-time operating system which can process information rapidly and make coordinated decisions with many other devices in the network at the same time.

 

Do I need a LCC 'Master' unit?

No! LCC is a peer-peer network. This means that any two (or more) LCC devices may communicate directly with one another without going through a central command station such as DCC or many legacy control systems require. A computer does make things easier to configure, but it is not a requirement for operation.

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What does the NMRA have to do with LCC?

Just like the NMRA set the standards for DCC over 20 years ago, they have now set the standards for LCC. A group of independent volunteers, both modelers and experts in electronics, have together developed the concepts, protocols, interface standards, and documents, for LCC. This OpenLCB group established the standards which the NMRA has approved as LCC. 

The NMRA has no vested interest in any manufacturer or product. They simply set the standards that all manufacturers may use license-free. 

 

What makes LCC so special?

Like people, each LCC product is unique. No more need for the user to assign and keep track of device addresses to prevent conflicts. New nodes may be added to any existing system with no data collisions… ever!  The protocol is also expandable for adding functions that we have not even thought of yet.

 

Are LCC products from different manufacturers compatible?

Yes, that is why having standards is important. Any manufacturer’s LCC products will interoperate with the LCC products from any others.

 

Is anyone making LCC products?

Yes! There are several manufacturers are already providing LCC related products, or will be in the near future. Some examples include TCS Train Control Systems, RR-CirKits, and Deepwoods Software (MRS).

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Special thanks to Dick Bronson at RR-CirKits for providing the structure of this LCC overview.