Digitrax Frequently Asked Technical Questions:

The following are some of the most frequently asked Digitrax technical questions.

Most prospective customers who are learning about our products and what they will do for the first time will enjoy "Which Digitrax Starter Set is Best for My Layout?"

More technical questions fall into several general categories covered below.

Either way, we invite you to review these questions and answers. This section will grow as we add new questions posed by users. We thank our customers and users for their thoughtful questions, and hope this section will help provide answers to them.

What special wiring is needed for Digitrax systems?

Click here for LocoNet Wiring information.

How does your Intelligent AutoReversing Work?

LocoNet's "ethernet like" architecture seems interesting and more advanced than the systems used by other DCC manufacturers. But, at the numbers we are talking about (a few controllers and perhaps 10-20 decoders), does it really make a difference?

If your system operates with a few throttles and other devices attached any of the commercially available systems will work today. But what about tomorrow? Remember when a hard-drive bigger than 32Mb seemed excessive- and remember when DOS had to change to 16bit FATs/ directories? Also, the LBA access change at 540Mb also once seemed unthinkable!!

The network structure of LocoNet is very important for your future system expansion. If you want to consider adding features like signaling, transponding and detection, the network structure will determine how easy this is to accomplish. To make expansion easy, Digitrax LocoNet offers a "plug and play" strategy that lets your system grow by simply plugging in new components. LocoNet is set up so that it can run systems of any size efficiently with the ability to expand system capabilities as you are ready.

As a cab bus type system is expanded to include more and more throttles and other devices, the first problem that you might see is delayed response time between when you send a command and when it is implemented on the layout. This is called latency. This means that when you change, for example, the locomotive speed there is a noticeable delay from the time you send the command and the time it is executed by the system. Digitrax LocoNet uses a carefully crafted CSMA/CD strategy (akin to the universally used "Ethernet" of computer LAN's) because it offers excellent performance for a scalable, practical and cost-efficient connection backbone for model railroad applications.

This simple CSMA/CD choice alone is NOT sufficient to ensure the performance demanded by today's users. Along with a message and access strategy, LocoNet employs a carefully crafted, balanced and synergistic combination of layers of physical, electrical, messaging, error control, data base and distributed system concepts. Our design concepts are validated by many existing state-of-the-art practices, such as the ISO layer model for open systems connection. Note that a simple communication bus and master-slave type architecture, as developed and used in mainframes in the 1960's and 1970's is not enough in the sophisticated true network environment of the 1990's and the next millennium.

LocoNet was developed to protect your equipment & time investments by incorporating expansion capabilities. We have committed the extra time needed to develop LocoNet as a scalable system architecture before we designed and offered ANY products for sale. As new capabilities like signaling, transponding, multiple PC control and a variety of advanced software and hardware come on line, the promise of LocoNet will be fully realized on model railroads around the world.

For more information about LocoNet click here.

I saw you are working with several product developers who are working on new LocoNet Hardware and software. Where does that stand?

We are working with several product developers who are working on new LocoNet hardware and software products. This takes a lot of Digitrax time and technical resources, but LocoNet is a commitment we are solidly behind to bring a variety of sophisticated products from other companies that all work together on LocoNet. Digitrax offers licenses for LocoNet and other Digitrax technologies on very reasonable terms to other companies who want to join the LocoNet family. We actively work with our co-developers to bring the best products possible to our mutual customers. This allows LocoNet to be professionally maintained and expanded in a rational way for the benefit of all model railroaders.

For more information about LocoNet Developers click here.

I am planning to have about 10-20 locos (not all at the same time) with decoders eventually on a medium sized layout. I would like a combination of handhelds and perhaps two computers for programming speed curves etc into decoders controlling signals, switches, sounds, extra equipment like layout lighting scheduling trains & following them on the screen using the computers as extra "handheld" controls.

This is exactly how we feel the more technically adventurous modelers will proceed. We see that a number of PC's will be connected over time, needing full access and allowing parallel and cost-effective tasking and distributed architecture. Only a real network, like LocoNet, will allow this growth with fewest barriers.

I have started to peek at the software available for DCC control, but am tempted to also control my layout via my own software. I am hoping that you will make low-level serial packet i/o (and packet creation, etc.) very easy and callable from some higher-level tools such as (GWBasic on DOS) Hypercard on the Mac. For example, as a Hypercard XCMD, which would allow hobby programmers to easily add user interfaces and a little scripted intelligence to a layout without becoming C++ PhD's I would be very interested in your plans for that.

We have already anticipated this wish of the more technical model railroaders. John Kabats's IBM DOS freeware software and documentation allows much of the "roll your-own" capability, now.

In addition, LocoNet Personal Edition is now available so that you can write your own non-commercial applications.

For more information on LocoNet Personal Edition click here.

Are common rail track detectors compatible with DCC?

We have a number of customers who are running Digitrax alongside their existing block detection circuitry. There are numerous block detection schemes and circuits, and we cannot cover all the variations here. Generally, it is necessary to isolate the block detector power supply and ground system of your existing block detector system from that of the Digital boosters. The most common detectors use "back to back" high current diodes to sense block current-draw. Detectors with "opto-isolated" or relay outputs will generally have no problem sensing current draw of a loco, etc., on the DCC current, and will signal the occupancy without any ground or power supply conflicts. Many DCC boosters, including Digitrax, work with both rails live and a separate system ground wire. This ensures no possibility of booster output voltages being "added" accidentally across adjoining booster power districts, and operation on catenary is possible.

If your layout is common rail, all you need to do is be sure to double-gap the layout between power sections supplied by different boosters.

Within the "power district" of a single booster you CAN have a common rail return between detection blocks as long as all the detectors are within the same booster and the detector power supply is isolated from other detectors and booster grounds. If you are not sure, simply disconnect the detector power supplies and reconnect them in stages while running the layout. If there is a conflict it will generally short-out one of the booster outputs and shut down. This will allow you to isolate the problem ground or power supply.

Also, what products are in the works for the future?

Keep an eye on our home page for information about what’s coming soon!

I hear the comment that Digitrax is an innovative manufacturer and company, what can you show to support this opinion?

We at Digitrax take pride in the fact that we have introduced many original and innovative ideas to model railroad control systems. We strive to be a leader in new product development and not to fall into the "me too" manufacturer category.

Our innovative product ideas include:

1) Digitrax Plug N Play Decoders were voted best technical innovation of 1997 by readers of Model Railroader Magazine !

2) Auto-reversing Boosters and Modules. We were the first to market automatic polarity reversing boosters for DCC, at our product debut at the National Train Show in Valley Forge in 1993. Many predicted that they could not work, or would fail to work for steam locos. Time has proven our concepts valid and a number of other manufacturers have used these concepts in other products.

3) 128 speed step operation and user customizable decoder speed tables. We felt fine speed resolution and locomotive control and throttle "feel", to be of paramount important to the serious modeler. Today the DCC industry has followed Digitrax' lead with most high end decoders offering 128 speed step capability.

4) Mobile decoders with onboard functions: From our first decoders we have always offered usable extra function leads beyond basic constant lighting. Our FX decoder versions offer another level of functionality, allowing the user to program sophisticated light effects that are integrated into the decoder operation, such as Ditch Lights etc. Other manufacturers have tried to imitate the look of Digitrax FX effects by using simple blinking light algorithms but they are just not quite the same!

5) Sophisticated but simple Network connectivity for an expandable system. Digitrax LocoNet is a revolutionary departure from the centralized bus concepts of other systems. Simply put, this allows Digitrax users to plug and play to create as simple or sophisticated system as they wish. There are no worries that the system "does not have enough horsepower" to grow in the long term. This is guaranteed by the LocoNet network design philosophy. The prioritized "event driven", rather than "polled", nature of LocoNet ensures the system will be able to maintain quick response rates as you add more components to your system.

6) Advanced logic in stationary decoders. The DS54 stationary decoder is an early example of the sophisticated network and distributed system capabilities that the LocoNet design embraces. The DS54 not only operates as a simple turnout decoder on DCC compatible systems but it also offers Digitrax users a LocoNet feedback/input module that incorporates user programmable logic capabilities. You can setup the DS54 to control local animation and logic tasks separate but in cooperation with LocoNet or DCC commands. This advanced "Attached Logic Module" concept is expanded and incorporated into a number of future Digitrax LocoNet products and those from other LocoNet compatible manufacturers.

7) Cost effective Decoder harnesses. The Digitrax 9 pin plug on our HO wired decoders lets customers share a few common decoders amongst a fleet of locomotives. This approach is really popular with clubs. Once a fleet is upgraded this way with low cost harnesses, users have "plug and play" capability of using a small number of decoders in a larger setting. The Digitrax 9 pin plug has become an industry standard and is used by many companies that make DCC compatible products.

8) System upgradeability that is "plug and play" and demonstrated. Our users can attest to the fact that Digitrax has really delivered on the promise of straightforward "upgradeability". We have done this in a number of ways, and do not require users to "tear into" or modify delicate electronic equipment.

The exciting new addition of radio and infrared capabilities to the Digitrax system only requires that the user add the UR91 radio/IR receiver or UR90 IR receiver to enable the system to accept input from new radio throttles or IR throttles. Existing DT300's & DT400's can even be converted to radio throttles!

For example, the upgrade path from Zephyr to Super Empire Builder to Super Chief is simple and cost effective.

Our DCS100/Super Chief offers a "plug and play" upgrade option to all existing LocoNets and introduces a whole new range of sophisticated system possibilities that are seamlessly integrated into the LocoNet design. Many expanded DCS100 features are already incorporated and accessible from all Digitrax LocoNet throttles we have shipped over the years!. No field changes or upgrades are needed- the components were designed and tested for these features before they left the factory. Note that these features are incremental additions and not just problem or bug fixes.

The addition of multiple computers and feedback onto the LocoNet system has been "plug and play" and designed into the original system architecture, no changing of components or IC's!. Having a real network strategy allows us to add all types of PC's to the same network, as applications are developed.

The Digitrax philosophy of modular expandability, and the LocoNet distributed type of system capability allows us to add new innovations directly to the LocoNet network without obsoleting existing products. Over the next several years, the strength of this strategy will be more apparent, and we find current users grateful we took the extra time to "think out the future" before designing or shipping any products.

9) Wireless Digitrax Command Control. Digitrax supports both radio and infrared links for wireless control of the layout.

10) Digitrax Transponding Technology. Advanced two way communication between the command station and decoders on the layout opens many possibilities for layout control. With transponding decoders and receivers, you can know where your locos are located on the track and you can identify each loco independently.

11) There are many more Digitrax innovations past, present and future so stay tuned for even more fun coming your way!

Our innovative "Corporate Culture" includes

1) Our Digitrax 'Corporate culture' is not limited to a "list of firsts". We are a full time professional company. Before we started Digitrax, model railroading was our hobby and still is today. From our experience with the model railroad industry, we decided early on that Digitrax would be run as a "real company" rather than a "basement operation." From the beginning we have strongly emphasized customer service and good engineering designs in an effort to bring a new level of professionalism to the hobby. This effort has really paid off.

2) Digitrax has always supported N-scale in all of its offerings and is committed to that marketplace, not as a second priority.

3) Digitrax carefully designs its products to have sufficient power and fit the tight space requirements demanded by many installations in all scales. We go to great lengths to be conservative when we state the current ratings of our products so that customers will be able to rely on excellent performance from our products.

4) We were also the first meet our obligations to ship DCC systems that were tested and passed US FCC Class B RFI requirements.

We hope you’ll enjoy your Digitrax products and if you have any ideas that would make your experience better, please let us know!

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Page last updated 01-30-03.