Digital Command Control (DCC)

Lenz LH100 Controller

Lenz Easy-DCC

The Meramec Valley & Pacific Lines Layout is operated using digital command control v3.6 manufactured by Lenz. The layout is divided into two power districts – an upper and a lower. The set-up includes one LH100 Dispatchers Throttle, two LH90 Engineer’s Throttles, an LZV100 Command/Power Station, and two LV102 5-amp Power Stations. A Lenz XPA XPressNet Phone Adapter is also a part of the system. The now-discontinued XPA allows any 900mHz (or greater) cordless phone to be used as a wireless throttle. The RR&Co. software allows an unlimited number of iPhones to be used as wireless throttles. Various XpressNet ports are located around the layout using both Lenz LA152 Adapters and 5-pin DIN plugs. The DIN plugs have been coupled with LEDs to indicate network status.

LS150 Turnout Decoders

Main-line turnouts on the MV&P are switched primarily by Tortoise (TM) switch machines, which are controlled by stationary decoders from both Lenz and NCE. Lenz LS150 Turnout Decoders are connected to most of the Tortoise machines and several Atlas (TM) switch machines. The LS150s operate both slow-motion Tortoise machines and coil (Atlas) machines, but a couple of diodes need to be included when connecting an LS150 port to a Tortoise. Each LS150 can control up to six turnouts.

NCE Stationary Decoders

Snap It and Switch It stationary decoders from North Coast Engineering (NCE) are also used to operate several of the layout’s switch machines. Snap It decoders are designed for Atlas machines and Switch It decoders are for Tortoise machines.
NCE now makes an eight-machine decoder called the Switch-8 (TM), which will power only slow motion machines like the Tortoise (TM). As mentioned earlier, the Lenz LS-150 can power both Tortoise and Atlas machines – a possible advantage if you still have a few Atlas switch machines left on the layout. Some of the NCE Switch It decoders have given me problems with the Lenz system. They won’t hold their address, and they sometimes lock up. I’ve not been able to determine the cause.

Computer Interface

A Lenz LI101F allows the Lenz DCC system to connect to one of the com ports on my Dell computer. (Lenz also makes a USB interface, the LI-USB.) Connecting the DCC system to the computer allows me to easily program most decoders using Decoder Pro (TM) software. I also use the computer to run Railroad & Company’s TrainController software to assist with layout operation. CTI hardware used to connect to the computer via another com port for my signaling system, but now connects via a USB port.

Block Detection

Track sections on the layout are divided into blocks. Occupancy status within each block is monitored by a current-sensing Lenz LB101 Block Occupancy Detector. Each LB101 can monitor two blocks. Output from the block detectors is fed into Lenz LR101 Feedback Encoders. One LR101 can accept the input from four LB101s. Because each LB101 can monitor two blocks, one LR101 encoder can handle eight track sections. Each LR101 communicates changes in block status back to the command station by way of the XpressNet. This information is then transmitted to the computer.


Mike enjoys family, music, computers, photography, travel, trains and most all facets of model railroading, especially ops.

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