Checklist for Choosing a Digital Command Control System
Summary: This article is a guide to Choosing a Digital Command Control System.
There are many variables which will enter into your decision, this is just a guide to help you make a choice. Read on for what you should look for.
- 1 Choosing a Digital Command Control System
- 2 Interfacing
- 3 Conclusion
Choosing a Digital Command Control System
Before selecting a basic or advanced Digital Command Control system, you need to ask yourself a few questions. It is a big investment and you will be using it for a number of years, so consider what you need now and will possibly need in the future. Choosing a low cost system may not be the best investment you will make in DCC, so consider all your options.
- How many locomotives do you plan to have in operation?
- Do you want to use sound decoders?
- Is the system expandable in the future?
- Is control of turnouts and other accessories in the plan?
- How many operators do you expect on your layout?
- Will two or four digit addressing be used?
How do you relate to computers? Do they like you, or seem to be out to get you? Did your VCR permanently display 12:00?
These are important questions. If you are very technically literate, that is an asset. If you are a technophobe whose very touch upsets electronic systems, then a full featured, top of the line, sophisticated DCC System may not be your best choice. It also pays to look at some of the European DCC brands, as some of their systems offer features not found on other DCC brands, such as a Graphical User Interface and automation capabilities.
You have two choices: a Basic DCC system or a Starter Set. What is the difference?
Basic Digital Command Control
While they are Digital Command Control Systems built to meet the NMRA DCC Standard, they are usually low cost. With the low cost comes a price: They may not have all the features you need, or just a basic set of features. They may even limit the number of addresses you can access. Often they can come in a package that resembles a power pack.
Another issue is future expansion capability: Many of these systems have limited expansion ability, and often can require expensive upgrades to break out of the limitations imposed by the system.
Some basic systems may lack the capability to control stationary decoders or more than 10 locomotives at once.
A Starter Set is the next level for a DCC system.
While these are also Digital Command Control systems, they are much more capable, and their price reflects that. Companies such as Digitrax, NCE and Lenz offer starter sets. Don't be fooled by the term "starter set", as they are full function DCC systems, built to offer you all the features DCC has, and have future expansion in mind. Should you decide you want to do more, accessories can be purchased to give you the features you want, such as stationary decoders to control turnouts, or the ability to interface with a computer.
A Starter Set can range from a basic, entry level system package at the low end of the price spectrum to an expensive package with wireless throttles at the other end. Everything you need to form the foundation of your Digital Command Control system is in the box regardless of price. The system will not put limits on what you can do in the future, expansion is usually much easier too.
Number of Locomotives
If you only want to run one or two locomotives, a small low current system will be adequate. Most of the DCC systems on the market can deliver from three to ten amps of current to the track. A system designed for 5A (amps) or less is adequate for a small number of locomotives.
To determine how much current you need, just prepare a power budget. Consider that the average HO locomotive will have a current draw of 500 mA (milliamps, in this case, 0.5A). If you have 10 locomotives you need ten times 500mA, or 5,000mA. Which is 5A. Now, your locomotives may draw more or less current. Larger scale locomotives will also have a higher current draw, so budget accordingly. A sound equipped locomotive will also require more current.
If you only have three locomotives, the budget would be 1.5A, so a three amp booster would be more than adequate. Even with sound, you would probably be OK.
Number of Throttles
Another issue is the number of throttles the system can support. Maybe you don't plan to have operating sessions with 20 throttles in use. Or maybe you do...
Some systems may limit you to how many throttles it can support. Others can support a large number, with no problems. Another issue is the throttle network. Some implementations start to have problems with a large number of throttles and other devices in use, which leads to lag and network issues.
How difficult is it to interface the throttles to the throttle network? Are connection points easy to install and available at reasonable cost?
Or you want to have only a few throttles...
Some systems do not offer handheld throttles, others may allow you connect additional throttles. Throttles are specific to the brand of DCC system you chose, and you cannot use another manufacturer's throttles.
Another issue is how do they feel in your hand? Comfortable or bulky? Is there a display, can you read it easily? Does it display enough information? How does the throttle knob feel? These are all issues that can be important to you. Be sure to investigate the throttle's feel before making a purchase.
Tethered or Untethered?
This is another question: Do you want to be able to operate with wireless throttles? They can be radio, or infrared in nature.
Can you add wireless operations later, or do you have to invest in a wireless system right from the start? Some systems will allow you to buy wireless throttles and associated components to obtain that capability. Others may not allow that, or have an expensive solution.
WiFi Throttle Capability
An alternative is a WiFi throttle, using your iPod, iPhones, or Android devices. To use this additional components are needed, in the form of a wireless router and a computer interface, plus a computer running the software to process the signals from the throttle and send them to your command station. It is also necessary to install appropriate software on your device to enable it as a throttle.
The wireless router can also be used with your computer network, and allow you to wirelessly connect to the internet as well. Be sure to chose one that will work with your handheld devices.
ESU Mobile Control II
ESU has launched a small, handheld wireless WiFi throttle based on an ARM processor running Android. It can interface with their command station using WLAN (Wireless LAN) or USB protocols.
Currently it is only supported by ESU Command stations but ESU is willing to work with other systems. It will supercede the ECoSControlRadio.
If you want sound, you need a DCC system with the ability to control a sound decoder. For this, additional functions are needed, and the DCC system needs to be able to provide access to them. Some may limit you to only several functions, where a more advanced system will offer F0 to F12, or even more. Since sound decoders demand more current, the current limit (amperes) of the booster may not be enough for your needs.
The ability to address your locomotive fleet is important. Some systems may impose limitations, such as only 10 locomotive address, or limit you to a 2 digit address. If you want to use the locomotive's four digit number, you need a system that supports a 4 digit address.
Some basic systems limit the number of addresses available, the number of trains in operation or impose two digit addressing because their software doesn't allow for those features.
If you are interested in Multiple Unit operations this is a necessary feature. All DCC systems offer Basic Consisting, while the more advanced systems can offer Universal or Advanced Consisting, which offer a lot more operating flexibility.
Again, this is determined by the software in the command station.
Sometimes called Accessory Decoders, these are used to control switch machines. Some can be only controlled from the power or track bus, while others can be controlled by the throttle network as well. Most DCC systems can interface with a stationary decoder, but some basic systems may not be able to control them. The commands and addressing used is different, and the software in the command station must support that feature.
How difficult is interfacing the system with a computer. Yes, DCC operation is possible without a computer, but for some things, you can't beat a computer with a full keyboard.
- Cost of an interface device?
- Is there an interface built in (Serial or USB)?
- What type of connector is used?
- Is software only available from the manufacturer, and if so, how much does it cost?
- Are any limitations imposed by the system?
- Does it support JMRI
This guide should have given you some pointers on what to look for in a DCC system. Be sure to explore the rest of the DCC Wiki for more information and ideas.
Also see the Introduction to DCC section for more on DCC.