Playing with DCS

This page is intended to give some news regarding what may be coming in the way of official MTH DCS products and also give some ideas on adapting them and/or using them in alternative ways.

Having problems with DCS?

If so may I recommend that you take the time to read the pages that Rayman4449 has kindly made available. He has considerable experience running multiple locomotives on lengthy sections of outdoor track and provides many suggestions to help solve the rarer as well as the more common queries regarding DCS.

Protosound 2 upgrade kit

MTH has already put together a kit for those people who might want to upgrade an original Protosound (1) locomotive to Protosound 2, it is equally useful in providing all the main components that are needed in converting a traditional non-digital locomotive unit to DCS with full motor, lighting, sound, smoke and/or coupler control. Actually they produce two kits, one intended for steam locomotives and the other for diesels or electrics. Both contain a decoder board with heatsink mount, a tach reader (which, if there is something to mount the supplied striped sticker on, will allow you to synchronise speeds with your other DCS locomotives), backup battery and charging socket, speaker and a full wiring kit. The diesel version contains two solenoid activated couplers, a full set of lighting including a Mars light, headlights and ditch lights. The steam version only has the one Proto-coupler, headlight and running lights, a wire that can take a timing cam input from the drivers to that the chuffs can be synchronised to the piston movements and power output for a smoke unit (pulsed so that it will puff if your smoke unit can take advantage). The kits are intended for O gauge and larger locomotives and will cope with a 5 amp current drain. O gauge couplers are provided.

The current product is Protosound 2 standard. I have been told that a Protosound 3 type kit will become available which will allow control via DCS or DCC (or traditional variable voltage with bell, whistles and such controlled using pulse codes).

I have also been told that a smaller Ho sized kit is under consideration. I think that producing this would be a very sensible strategy (particularly if they had versions that would plug straight in to "DCC ready" sockets as well as "solder in" kits for older models) since the range of Ho locomotives that MTH produces, although growing, is nowhere near the breadth of choice that they have produced on O gauge whereas, if all the current and defunct manufactures of Ho locomotives are bundled together, a truly staggering choice of locomotives are available. If you have a peek at one of the "Art of Brass" books or even a Walthers catalogue you should understand.

The MTH kit is not as cheap as some decoders on the market, however it is not just a motor control unit but has a full blown sound system included and comes as a full kit with lights, speaker and powered coupler(s) as mentioned above. One of the advantages is that MTH has already developed sound files for their O gauge ranges and the sound effects are equally valid in other scales. These sound files can be downloaded for free from the MTH website and if you have access to a TIU then you can load up the decoder with these sound effects. Even if the MTH range has not covered your preferred steam, diesel, electric (or turbine) locomotive there may well be something that at least has a similar sound to the prototype.

Battery power and remote control

If you run an outdoor layout with track power there is always the hazard of track cleanliness. If you have stainless steel rail the problem is not as bad as for nickel-silver which again is better than brass in terms of oxidisation. I use brass rail for gauge 1 outdoors and it does oxidize quite quickly. If you happen to run live steam then there is the further risk of water and oil based deposits fouling up the conductivity. Generally I have found that the DCS system will operate with track that has not been cleaned to perfection, maintaining power to the motors is not really the problem as DCS operates as a cruise control system when it is not receiving fresh commands and the flywheels will smooth out any small loss of power, what I find is that some of the time a command can be missed. Generally the change speed commands are the least effected, it is more often non-critical effects such as stopping the bell that may not trigger when you want. Although I am not privy to the internal workings of DCS I suspect that the reliability of the change speed is due to multiple commands being issued. DCS works with mile an hour speed increments so if for example you want to go from 5 to 9 mph I reckon that as you hold move the thumbwheel (or hold the increase speed button down) individual 6, 7, 8 and 9mph speed commands will be sent in rapid sequence and, since the DCS decoder obeys its own momentum simulation, the higher speed commands will override any mangled prior commands before the locomotive reaches the intermediate speed. In comparison if you press the start bell button you are likely to hold it down until the bell actually operates whilst to stop it the operator is more likely to just stab the button since the sound decoder gives an accurate rendition of the bell tailing off and an instant stop is not expected. If the stop bell command suffers from poor track conductivity at that instant and is not received clearly by the decoder then the bell will continue ringing until the command is transmitted and received cleanly.

If you like the idea of a walk-around handset then the TIU and remote has a maximum range of around 50 feet as supplied. Remember that that is 50 foot from the handset to the TIU rather than handset to locomotive so, if the TIU is situated at the mid point of a 100 foot straight you may still be in range. (if you want to try and boost the handset-TIU range you might care to look at this suggested TIU aerial modification from Raymond).

There is however an alternative that does not need the track to carry either the power supply or the DCS command signals. MTH now produces a small and relatively cheap DCS controller called the Commander Remote. The handset is very compact and does not have anything like the number of individual control buttons that the TIU handset does but all the critical controls are there. The receiver is quite compact, definitely small enough for an O gauge or gauge 1 boxcar or coach. Rechargeable batteries need not be expensive if you hunt around. Three small 6v lead acid batteries will provide 18 volts, as would fifteen Nimh cells. If a maximum running motor load of 3 amps is assumed then a 3 Ah capacity battery should provide an hours worth of motion and 3Ah capacity "AA" cells are now available. The remote link on the Commander Remote is via infra-red which has a relatively short range and needs line of sight to the receiver. Fortunately there are i/r range extenders that work via radio and there is at least one version of these that does not require any adaption of the Remote Commander or the handset. Using this method all that is then needed is a small amount of wiring in the battery cum receiver car and a small amount of re-wiring in the locomotive. The handset is now effectively converted to a radio unit, the receiver hands the i/r signal to the Remote Commander and fresh wiring carries the battery power through the Commander with the added DCS signals on to the locomotive decoder. If the locomotive has a cavernous boiler or tender, or has a massive body like an ALCO PA diesel or the GG-1 electric then the whole remote control system may not require a "battery wagon" although using a separate piece of rolling stock will give extra flexibility if you have other locomotives.

The locomotive is adapted to so that the wires going from the track pick-ups to the DCS decoder are cut and dpdt switch is wired in such that the wires from the decoder are connected to the central switch contacts, the wires to the pick-ups go to the contacts at one end and from the other end a pair of wires needs to be run to the output terminals of the Commander remote (via whatever connecting plugs and sockets you deem suitable) . Flicked one way the switch isolates the track pickups and the battery pack powers the locomotive, flicked the other and the wiring circuit (if not the actual wiring) returns to factory stock with the battery pack isolated. If the capacity of the batteries that you prefer to fit will not stretch to the run time that you need then the design readily be extended (assuming that track power is available) so that the track power goes to a bridge rectifier and the rectified output then feeds a charging circuit for the batteries, even if the track was not conducting particularly well the DCS decoder would still have the reliability of battery power over all the dead spots and recharging would recommence as soon as proper contact with the rails was reestablished.

Computer control of a TIU

Mike Hewett has generously shown that it is perfectly possible to automate control of a TIU using a programmable circuit board that he calls a "stamp". He does not go into any fine detail as to the program that he uses to drive the stamp but he establishes that the stamp can be used to record the output of the handset and that the stamp can then be controlled from a computer to output the recorded codes to the TIU. In theory, if you knew the full details of MTH's coding, the TIU could be driven directly from an RS232 computer port without the need of a further programmable component. He has chosen to have overall control of his O gauge layout by means of a touch-screen computer running CTI Electronics "TrainBrain" software with various CTI accessory board controllers on a CTI network. One item on his CTI network is a dummy CTI Yardmaster controller board, which would normally be fed with two bytes of data to set 16 relays but Mr. Hewett has made an adaption so that those two bytes are sent to the stamp. The stamp has been programmed such that one byte is taken to represent one of the locomotives for which the commands have been pre-recorded and the second byte selects from the seventeen major commands that he has recorded in sequence. The stamp then looks up and outputs the sequence of twenty or so bytes that were originally recorded against that command for that locomotive and sends them to the TIU. Naturally if you can drive a TIU to control O gauge locomotives you also have the means to control any Protosound 2 or Protosound 3 equipped locomotive in any scale or gauge, whether gauge 1, Ho or reproduction tinplate.