Page Originated 08/2000
Page Updated 04/2008
Page Updated 04/2011

OVERVIEW ON ADAPTING WIRELESS CONTROL TO LENZ DCC

It is possible to make your own tetherless (radio controlled) cabs for use with the Lenz system..

With Michael Stimac's engineering help, I proceeded to add a wireless facility to my Lenz LH100 cabs. The same technique is probably adaptable to any manufacturer's system that has a pushbutton cab with simple (no dual mode) buttons.

A company called Remote Control Systems of Australia makes a transmitter/receiver product. They advertise in some of the magazines. It is based upon a garage door control system product used in Australia. The RCS system costs about $100 - $125, I estimate, since I purchased mine several years ago.

The transmitter is about the size of cigarette pack, has 4 "buttons" (pressure sensitive areas on its surface), and has a long battery life (Michael's prototype was done around 1993, and that transmitter still has its original battery.) The range is 300 feet. The signal transmitted is digital via FM. As I recall a large number of frequencies is available.

[The systems I use have four controls. RCS now advertises eight controls; I have no experience with the latter, and suspect they are a simple expansion of the four control system described below. I think when you read "four" below it is safe to substitute "eight" for my figure of "four" except that the number of conductors in the cable may increase by four (the four additional buttons) or five (the four additional buttons plus the third ground circuit).]

The receiver from RCS is a printed circuit assembly. It requires power, and has four outputs each of which becomes a closed circuit when the associated button on the transmitter is pressed. The circuits do not latch.

To adapt this to Lenz, I decided which buttons on the LH100 I wanted to control: the single step throttle and brake buttons, the change direction button, and the 0 button (so control of a loco could be verified by toggling its headlight.)

Michael determined where to make solder attachments for the button and ground circuits on the LH PCB. I needed two of the three ground circuits. So eight connections were needed between the LH and the receiver: four for the four buttons, two for ground, and two to power the RCS receiver.

A cable was added to the LH100 using a Level 5 jumper cable (used for LAN patch panels) which has eight (maybe nine) wires internally. Its RJ-style plug made for easy plugging/unplugging of the LH to the receiver, and it wasn't so large as to be unwieldy when not plugged into the receiver. The Level 5 cable was cut to get rid of the plug on the other end - I cut mine in 1/2 and used each 1/2 for an LH100. Level 5 cables and sockets come in a number of colors, so it is possible to color code the receiver box by the color of the Level 5 socket, and the transmitter with a colored self-adhesive dot. As I recall the wires within the cable were also color coded, making it easy to make correct corresponding connections to the receiver.

The receiver was mounted in a plastic intrument box. A DIN plug connects a DIN socket mounted on the box to the Lenz XBus. The LH100 is connected to the DIN socket. The Xbus power is also connected to the receiver to provide its power. An RJ socket for the Level 5 plug is also mounted on the box and is connected to the receiver PCB such that each LH100 button's circuit and its corresponding ground are on as separate receiver output. A three foot length of #22 solid wire is the antenna.

Pushing a button on the RCS transmitter will cause the receiver to close its corresponding output, which, via the Level 5 cable connnected to the LH100, connects the LH100's button circuit to its ground circuit, electrically pushing the LH100 button.

All buttons on the LH100 including those connected for wireless control work as before, and they work regardless of whether the LH100 is plugged into the receiver box's DIN socket or into a normal connection to the XBus.

To use the LH100 in wireless mode, plug the receiver box DIN cable into the XBus. Plug the LH into the receiver box DIN socket, and plug the Level 5 cable into its socket. Set the address you want to control on the LH100. Now just leave the receiver box/LH in an out of the way place and use the transmitter with the same color sticker as the Level 5 socket on the box to run your loco.

How does it work? Quite well. One has to be careful to center their finger on the transmitter's pad or it won't transmit when pressed. The transmitter helps this by providing small peak in the center of the pad which is easy to detect by feel, and by making a barely audible chirp when it transmits. It tranmsits as long as pressure is applied to the pad. I found transmissions of at least 1/2 second were necessary to get the receiver to react. Selecting the correct one of four buttons by feel hasn't been a problem.

I have four LH100 so converted. Since the layout hasn't progressed to the point where more than two trains can be run at once (and not all locos are converted yet), I can't comment on simultaneous use by multiple engineers.

At first it was difficult to get used to not having a display in front of me for the loco I was controlling. Now I like it because the engineer's concern becomes speed and train situation, not speed step (artificial to me) and train situation. Sometimes I lose track of direction and make a false (wrong direction) start (headlights are wired/mapped to be on regardless of the direction setting.)

Drawbacks:

Cost
Since you need a pushbutton cab and the RCS components for each engineer who will have wireless control.
Warranty
You will probably void your manufacturer's warranty and/or support if you start soldering to their cab's PCB.
Complexity
If you want to use all eight buttons on the transmitter for control, depending upon the design of the cab you may need a larger (more circuits) cable than a Level 5 cable. You might have to use a larger connector such as a DB25. Some of that may be immaterial because one implementation would be to build the receivers permanently into your system's cab bus. Then you would only be making connections between the cab and a receiver when you wanted to enable wireless control.
Sound
For sound equipped locos most will want control of more than four buttons.

Please don't ask me for more details on how to do it. If you don't understand from the above description how to make the conversion yourself, you probably won't be successful no matter how much assistance I provide. The likely result is that both of us would end up being very frustrated.

If you understand the concepts and approach but have some minor implementation detail questions I would be glad to tell you how I implemented that detail, and will offer any alternative approaches that come to mind. If there are holes in what I have written above I will update this page to fill them.

I provide the above information from the point of view of being helpful, not to solicit business.

CONTACTING ME

Interested in learning more about 2-rail O scale? Please visit the O Scale Kings web pages.

These web pages were designed and implemented by Rod Miller.