Digitrax Chief
Digitrax has always had a company philosophy of releasing their products in a logical sequence, particularly after the applicable standards and RPs are adopted. A.J. Ireland doesn't want to go the route of sending out periodic EPROM updates for his systems. Instead of having one system capable of being upgraded as the standards and RPs change, he would rather have several different systems capable of different levels of capability. In spite of this, should there be a major change in DCC standards, Digitrax systems can be updated.
Their first release, the Challenger, debuted as an introductory system even before the NMRA had adopted the basic standards, however it has received a conformance warrant. Challenger is considered an entry-level system that provides very basic control (direction, speed, lights, acceleration and deceleration rates and mid-point voltage). Control for only 16 locomotives is supported in groups of four. Their second system, the Big Boy is an intermediate-level system that offers control of 22 locomotives, 128 speed steps and user-loadable speed tables. Digitrax just started shipping their latest system, the Chief, which incorporates the EPF. Among the advanced functions supported by the Chief are four-digit addresses, basic, intermediate and advanced consisting, ability to operate 120 locomotives, operations-mode programming and a lot of other features I'll get to later.
The basic component of the Chief is the DCS100 which is a combined command station and 5-amp auto-reversing booster. As with all other Digitrax systems it's up to the purchaser to provide a power supply. Four-digit addressing allows you to enter over 9,000 different addresses although only 120 can be operated at one time (assuming you have enough boosters to power that many). In addition to locomotives, you can control up to 999 switch addresses. Several different types of programming are supported including service mode, which means you can program locomotives on a separate track while trains are running on the mainline. Also, operations-mode programming allows you to program locomotives on the mainline, however only advanced decoders support this mode. The Chief's programmer can also read as well as write decoder settings.
Multiple-unit consisting options include: 1) basic where all decoders in the consist are given the same address, and 2) universal where any type of decoder can be used, even a locomotive without a decoder. Advanced consisting is basically a subset of universal consisting. The big difference here is that with advanced mode the consist address is stored in the decoder instead of the command station reducing the amount of information the command station must keep track of. (I'll cover more of the details of advanced consisting when I go over decoders.) The Chief also has the ability to generate trinary signals used by some European decoders at the same time as the DCC signal. This feature was added to provide support for current owners of trinary decoders.
Digitrax has also added a fast-clock feature to the Chief. You can control whether or not the fast clock displays and the rate. There are several other options that allow you to customize the system. For example you can have the key clicks and beeps on or off, ballistic or linear tracking, control purge times and set the default new decoder type. However the most innovative addition is aliasing. Aliasing allows you to assign a four-digit address to your old two-digit decoders. This means that if you have a decoder assigned to address 11 installed in locomotive 1480 you can assign an alias of 1480 to that decoder. In effect it converts your two-digit decoders into four-digit decoders! I guarantee that you'll see this option very soon in several other systems that upgrade their software with a replaceable EPROM.
The other component in the Chief system is the DT100 throttle. Like earlier Digitrax throttles the DT100 has two binary encoders (knobs) for speed control and various programming functions. For example you can browse through all the possible addresses (all 9,980 of them) very quickly using the encoders in ballistic mode. (Ballistic mode means the response to the encoder depends on how fast you turn it.) It also allows you to control lights and eight functions, see switch positions, set up and control routes. Route selection allows you to preset up to 32 sets of switch positions with as many as eight switches in a route. The advantage of this is that you can dispense with diode matrices to set up switch routes. Please remember that for any of the options I mention that involve controlling switches you'll have to install stationary decoders and in some cases, feedback modules.