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		The most advanced DCC system of the world


	The following pages you won't find anything that is today considered a "digital standard", such as 128 speed steps, 10000 addresses, load compensation (BEMF) etc. but rather features which distinguish ZIMO from all others that make up the rest of the DCC market.

	. . . Realistic railway operation with "signal controlled speed influence"

	Imagine, trains are running according to a timetable, obeying all traffic signals and rules. They find the way automatically in to your station to their assigned station platform track and stop for the length of time allotted to them. Some trains may not stop at all in your station on their journey to a far off destination. Once they leave your station they find their way back to their place in a hidden station until their time is up to visit your station again. This all happens in the "back ground" while you concentrate on putting a goods train together with your favorite switcher engine. This kind of prototypical operation is possible with ZIMO's "signal controlled speed influence". It will limit speeds, slow down or stop trains on any part of a layout, automatically. Every train will respond to these commands. And yet you can still work as an engineer on any train and operate the engine in manual mode. It is now your responsibility to obey traffic lights and operate in a safe manner. It can't get any closer to realism than this ! You can finally operate your whole layout by yourself or for visitors without the help of your operating crew. There are different ways used by other manufacturers to achieve this. They all fall short of realistic operations. Here is why: The "conventional" method: The power to the track section belonging to the red signal is switched off. Disadvantages: Lights are off (also sound, etc), no control over train in a speed limit or stop section and no prototypical smooth stops and starts. The computerized method: The actual position for all trains is calculated at all times by a computer; the speed influence is made via normal commands. Disadvantages: Computer and a lot of associated equipment (occupancy detectors, etc.) distributed all over the whole layout is necessary right from the beginning; no unrestricted (manual) operation of trains possible, as computer would lose track of the trains position. The brake generator method: In certain track sections the digital control information is replaced by broadcast commands that only contain speed information. Disadvantages: No control over trains in a stop section via cab; complicated setup to avoid bridging the gap (both-rail) between sections by locos and cars. And then there is ZIMO´s only "signal controlled speed influence": Speed limit bits (stop and 5 speed steps) are fed into the data stream, which do not replace the individual loco instructions coming from the cabs. So all disadvantages mentioned above can be avoided and some good features are added: Full control over headlights and other loco functions (steam, sound, etc.) is maintained at all times, even when stopped at a red signal and on sections with restricted speed, Overriding the signal controlled stop or speed limit is possible from the cab with the special "MAN" key, individual for each engine ! Acceleration and deceleration of locos is adjustable on an individual basis (by special configuration variables which are added to the normal NMRA set, found only in ZIMO decoders). Bridging the isolation gap between adjacent track sections does not cause short circuits or indefinable conditions. Only one rail needs to be cut and isolated (blocks). It is an economical method, too: no additional hardware is needed within the decoders, and rather simple electronic circuitry in the MX9 track section module allows the setting of speed limits to track sections. "Signal controlled speed influence" can be achieved with or without a computer. For a computer controlled layout the "STP" software takes advantage of this special ZIMO feature: The computer has no need to trace train numbers across the layout. No control commands are issued directly to any loco decoder; instead trains are controlled via track sections. An extra benefit to this method: manually driven trains as well as lifting an engine from one part of the layout to another is recognized automatically. Up to 9 computers may be connected to the same layout, should your layout grow that big ! Automatic block control using track section module MX9 with or without computer:

	. . . "location dependent function control"

	A feature similar to the signal controlled speed influence. MX9 track section modules and MX68 function decoder together are in control of: Selected function outputs of Zimo function decoders on predefined locations (track sections) in the layout. For example: An engine may blow its whistle at station entry or the coach lights come on automatically before entering a tunnel. "And", "or" and "not and" combinations are possible for controlling function outputs directly. ZIMO loco decoders will have this feature added later. Automatically programs the secondary address of the function decoder to the loco decoder. E.g. to "connect" all lighted coaches of a train to the loco presently pulling the train.

	RailCom = "Bi-directional communication"

	This new method of sending data through the track from the loco decoder to the command station or computer is being standardized by the NMRA during 2005. This will allow decoders and systems of different manufacturers to communicate with each other. One of the main purposes of this is to have a decoder confirm or acknowledge the receipt of a command issued by the command station (e.g. on the fly programming of configuration variables) and to locate the identified train number on the layout. This information can be used to automatically stop trains at specific locations on the layout, route trains through stations etc. ZIMO uses these functions for years already (see above) but can now, with the help of the NMRA standardized "bi-directional communication", be combined with decoders and systems of other manufacturers (provided they implement them). ZIMO is part of this from day one. The MX62, MX63, MX64, MX69, MX82 decoders are equipped with "bidirectional communication". Decoders sold before 2007 contain the hardware only but its software can be updated later also by the user with the Decoder update device MXDECUP. The time of implementation is depending on the success of the standardization at NMRA.

	CAN Bus

	One of the most important part of a DCC system is the data link (the "Bus") between the system components like command stations, cabs, modules for feedback information, etc. The differences among the systems in this respect are not that important when starting with a DCC application, but they will be crucial when expanding the control system. Well-known bus systems are the X-Bus (used by Lenz, Arnold), the Loconet (used by Digitrax), the NCE-Bus (used by Wangrow/RamTraxx), and the CAN-Bus (used by ZIMO/STP). The ZIMO CAN-Bus is probably the most powerful and reliable data link used in model railroad control today. It works as a Local Area Network (LAN) with multi-master capability; there is no time consuming polling by a central device. HIGHEST SPEED (115 kbit/s): This is more than any of the rival systems offer. Although a bus with lower speed would be sufficient if used as cab bus only, the ZIMO CAN-Bus shows its superior performance if, for example, hundreds of occupancy detectors and loco number identification boards have to transmit continually changing information to a computer (or to several computers). Thanks to this high performance, the ZIMO system doesn't need any separate cab and feedback buses. All data transmission is done within one network. HIGHEST RELIABILITY: The CAN-Bus hardware and software protocol is widely used in industrial, automotive and medical applications. The physical layer is similar to the well-known RS-485 standard, but with special capabilities in order to handle heavy traffic efficiently. Extensive automatic error recognition and correction are included in the CAN protocol. EASY WIRING FOR MOST APPLICATIONS: Only in cases of very large cable lengths (up to several hundred meters, about 1000 feet) should the CAN-BUS be installed as a "linear terminated bus" with resistors placed at both ends of the network, which means wiring point to point rather than a tree with branches. In most applications, up to 16ft. (50 m) but more likely up to 32ft (100 m), trees and branches are allowed without any restrictions. EASY TO WIRE: The ZIMO CAN-Bus uses 6 pin Telephone type connectors and cable. The CAN-Bus itself only needs 2 wires; other wires carry power for cabs and modules and various "grounds". CAN-Bus cables in various lengths are available from ZIMO. Alternatively, you can make your own cables by means of a special mounting tool (available from ZIMO or local electronic store). This is recommended for larger layouts (wiring of accessory modules, track section modules, etc.) in order to avoid waiting on shipments (and of course it is cheaper, too).
	OCTOBER 2009 (MAY 2006)