Transponding-Two Way Feedback

Characteristics Controlled by CV61:Some Digitrax Decoders use CV61 (one of the manufacturer specific configuration variables) to give you the following options:  Non-Directional Headlight Operation, Transponding Enabled or Disabled, & Split Phase Motor Drive for Märklin AC and Lionel Type motors.The look up table below shows the effects of different CV values that you can program into CV61.  CV values are shown in hex & decimal are the same in this case.TABLE 61: CV61 Values CV 61 Value Non-directional headlights Transponding Split Field Motor/AC 00 No No No 01 Yes No No 02 No Yes No 03 Yes Yes No 04 ...

Since 1999, Digitrax has produced function-only decoders with Transponding capabilities.  These decoders make it easy to add transponding and additional functions to locomotives with decoders that do not have transponding or enough functions.  These are useful for customers with older decoders produced before transponding was incorporated into Digitrax decoders.  They are also useful for users of decoders made by manufacturers that do not support transponding.The TF1 is a single output function decoder with Transponding capabilities. This function decoder adds an additional function along with Transponding ID capabilities to an engine with non-Transponding decoder capabilities or adds a single function along ...

Q:  Can I use non-Digitrax decoders on a Transponding layout?A: Yes.  If you want to add transponding to a decoder that does not have the feature, add TL1 or TF4 to the decoder.  Some non-Digitrax decoders that use supersonic features are not compatible with transponding unless you switch off the supersonic feature. Digitrax supersonic decoders are compatible with transponding and can be used in supersonic mode while transponding.

Q:  Can I use Transponding with existing Digitrax decoder installations?A:  Once transponder receivers are installed on the layout, you can run any transponder equipped locomotive. All current production Digitrax decoders are transponder equipped. Older Digitrax decoders models without transponders and decoders made by manufacturers that don't support transponding can add transponding by installing a TL1 or TF4 to the locomotive.

Q:  Will Digitrax Transponding affect my existing boosters, track wiring or locomotive pickups?A:  No. Digitrax transponding is designed to be sued with DCC compatible boosters made by all DCC manufacturers, track wiring & locomotive pickups without causing any damage or operational problems with existing DCC track signals. Unlike other "bi-directional" systems, no high current spikes are used by Digitrax transponding that can cause problems with boosters and wiring. Digitrax transponding does not require the replacement or modification of existing control equipment or infrastructure.

Q:  Which decoders work on Transponding layouts?A:All DCC decoders can be used on transponding layouts. However, only those decoders with Transponding capabilities turned on will issue a report each time they enter or exit a Transponding Zone.  All current production Digitrax decoders include transponding.Transponding can be added to any decoder by installing a TL1 or TF4.

Yes. Digitrax decoders with integrated transponding are shipped with transponding enabled but this does not affect the operation of existing layouts not outfitted for transponding.

If you want to use Transponding for bi-directional layout communication and are using Digitrax LocoNet, you will not have to add any "feedback bus" since this is already incorporated into LocoNet's design! If you want to use Transponding with a non-LocoNet system, you will need to add LocoNet. Non-Digitrax control systems require a separate feedback bus for the layout to achieve more limited types of bi-directional communication anyway so, you can simply add LocoNet instead of that feed back bus.

Transponding gives you operations mode readback of decoder CVs while they are on the layout (for decoders with this feature). Your dispatcher will know where trains and other equipment are located. Feedback from your transponding decoders lets you know the zone location and address of any piece of transponding rolling stock on the layout. This information can be presented on a display panel, your computer or even on your throttle. Feedback from the locomotive decoder also can provide information about the speed and other status data for the specific locomotive. With transponding, you can FIND the location of a specific ...

1.  Install BDL16 series occupancy detector(s).  BDL16, BDL162 and BDL168 occupancy detectors can be used together on the same layout.2.  Add RX4 transponder receivers to the zones you want to set up for transponding. (You won't need to cover every detection section on the railroad for effective coverage and reporting. Some areas will be detection only sections while others will have full transponding as needed.)  Use either two RX4s with your BDL168 to set up 8 transponding zones or use one RX4 if you only need 4 transponding zones.3.  All current production Digitrax decoders are transponder equipped. If you have decoders ...

Proven technology for bi-directional layout control without the need for modifications to your existing DCC system investment. Know the detection section and/or zone location and identification of any specific locomotive or other rolling stock equipped with a transponding device. Yes, now your dispatcher will be able to know "who you are and where you are"! Location and identification information are updated constantly on LocoNet and can be displayed on a track diagram. Adds operations mode readback of CVs to your layout. Data received by the system from mobile decoders can be used for display, automation, sound processing and much more. ...

On layouts set up for Digitrax transponding with transponders in locos and rolling stock and transponder receivers installed on the layout, the DT40x’s FIND Key is used to turn on the find command. The FIND function lets you see the zone location of transponders on the layout in your throttle display. To use the FIND Command: 1. The layout must have Digitrax transponder receivers (BDL16x & RX4s) installed and configured. 2. The loco or other rolling stock that you want to track must have a transponder installed.  This can be either a transponding decoder or a stand alone transponder. 3. ...

Testing the installed TF4 for correct transponder operation1. Place the unit with the installed TF4 on an empty transponding track section. This test assumes that the transponding track section is already set up, tested and is working before you start TF4 testing.2. Using a DCC throttle, select the TF4 address that was programmed into the TF4 and verify that the transponder detector identifies the presence of the transponder device. Depending on how you have set up your transponding reporting to the system, your system should detect the presence of the address in that transponding section.For example, if you have an ...

Installing the TF4 in the Loco or Rolling Stock1. Connect the TF4's RED and BLACK wires to the matching RED and BLACK track feed wires of an installed DCC mobile decoder.2. If the TF4 is used by itself, for example in a caboose or box car without a DCC mobile decoder installed, connect the TF4's RED wire to the right hand track pickup and the TF24s BLACK wire to the left side track pickup.3. No other parts are required to set up the transponder current pulses, since this is self-contained in the TF4.4. Install the lamps using the TF4's blue, ...

LocoNet typically supports a total cable length of up to 2,000 feet with no two devices connected by more than 600 feet of cable. LocoNet wiring is totally free-form. We do not recommend looping LocoNet back on itself.Making your own LocoNet Cables is simple and cost effective. LocoNet wiring consists of readily available wire and connectors. LocoNet uses flat 6 conductor wire and 6-pin RJ12 connectors. This kind of wiring is typically used for telephone wiring. Most Digitrax dealers can make up LocoNet cables for you. If you plan on wiring a large layout, you may want to invest in ...

A TF4 can be used with any decoder that is not transponder equipped to add transponding capability to the loco.  It can also be used in any piece of rolling stock with track pick ups to add transponding.  For example, you could use a TF4 to add transponding and lighting effects to a caboose if it is equipped with track pickups to provide power and signal to the TF4.A TF4 should not be connected to an existing transponder equipped DCC decoder unless the DCC decoder's transponder is disabled. This avoids having 2 transponders responding to the same address in the ...

Function-only decoders allow you to add additional functions to a locomotive with an existing mobile decoder.  Additionally, function-only decoders allow you to install lighting in passenger cars, as an example.Function only decoders also are used to add Digitrax transponding to early model Digitrax decoders and decoders from other manufacturers that do not have this feature.

1. Before using your TL1, set its address. This may or may not be the same address as a mobile decoder already installed in the loco or car depending on how you are planning to use the TL1. In the case of TL1s being used as a stand alone transponder or as a function decoder, choose an address that is not associated with another mobile decoder address in use on the layout.2. Connect the RED & BLACK wires of the TL1 to a service mode DCC programmer and program the TL1's address as you would any mobile decoder address.Follow the ...

Transponding is proprietary technology of Digitrax Inc.  Transponding works with existing DCC compatible layouts. RailCom is proprietary technology of Lenz Elecktronik. This is sometimes referred to as "bi-directional communication."  It requires modifications to existing DCC equipment for proper operation.The two methods are not compatible, they do not use the same technology.

Digitrax transponding works with Digitrax signaling system products. Transponding is not required to operate signaling systems however, the provision of transponding allows the possibility of the signaling system being able to automatically take control of trains that violate a signal aspect. Transponding can also be used to eliminate the "pushy pusher" problem that is characteristic of hardware implemented signal influenced speed control schemes.

Digitrax transponding does not use high current spikes so it does not typically cause radio frequency interference (RFI) issues with large installations as with some other bi-directional communication protocols.

Will I be able to use Transponding with other DCC systems?Yes. You will have to run LocoNet, instrument your layout and install TL1 or TF4 or transponding decoders in your locomotives. You can then use a computer on LocoNet to display position and ID information for transponder equipped locos. LocoNet will run independently of your existing non-LocoNet system.

Can I still operate a non-decoder equipped locomotive on my Transponding layout?Yes! Transponding will not affect operation of an analog loco (one without a decoder) on address 00. The analog loco will not transpond since it is not transponder equipped.

You can simply add a TL1 or TF4 to locos with decoders made by other DCC manufacturers. In the case of some supersonic decoders made by other DCC companies that are not transponding compatible, you will need to turn off the supersonic feature when you want to use transponding. Digitrax supersonic decoders are compatible with transponding and can be used in supersonic mode while transponding.

Once you have instrumented your layout for transponding, you simply add transponder equipped locomotives and you are ready to go. Digitrax decoders have been shipped with transponding included since 1999.  All current production Digitrax decoders are transponder equipped. Older Digitrax decoders models without transponders and decoders made by other manufacturers can add this capability by installing a transponder such as the TL1 or TF4 to existing DCC locomotive installations.  These transponders also add functions to the loco.

I understand that LocoNet is used for transponding "feedback."  How can Digitrax systems handle both DCC and transponding without interfering with other track level communication and without adding another communication or feedback bus like other system have to do?LocoNet is a true network with future expandability built in. Part of that future is here now with transponding. LocoNet was engineered from the very beginning with things like this in mind.If you are already using Digitrax LocoNet, you will not have to add a "feedback bus" since this is already incorporated into LocoNet's design! If you are using transponding with a ...

Program the TF4's Address & Function Outputs1. Before using your TF4, set its address. This may or may not be the same address as a mobile decoder already installed in the loco or car depending on how you are planning to use the TF4. In the case of TF4's being used as a stand alone transponder or as a function decoder, choose an address that is not the same as another mobile decoder address in use on the layout.2. Connect the RED & BLACK wires of the TF4 to a service mode DCC programmer and program the TF4's address as ...

  Q:  How can I write and read the Configuration Variables of Mobile Decoder on the mainline using the DT40x Throttle? A:  Operations Mode Programming, also known as Ops Mode, lets you program a locomotive decoder's CVs while it is on the main line. With the addition of transponding in Ops Mode, you can write and read back CVs in DCC locomotives equipped with most modern decoders while they are on the mainline. Some older decoders before Extended Packet Format was used are not able to do this.For example: A typical use for Ops mode programming would be to adjust an engines ...

Operations mode (OPs mode) programming allows you to program decoders on the layout instead of having to move them to a separate programming track.  This is a write only programming method.  If you want to be able to read back the values written to a particular decoder using Ops Mode programming, you will need to install transponding on the layout.  If transponding is not active on the layout, you must use an isolated programming track for reading back CV values.The extent of the area with OPs Mode readback available depends on how muchof the layout is instrumented for transponding. The ...

The FIND Key is used in conjunction with a layout instrumented for Digitrax Transponding and locos or cars equipped with transponders to find the location of those pieces of rolling stock on the layout.