A Decoder Tester is a device used to check a multifunction decoder for proper operation prior to installation or for troubleshooting purposes. Some also include additional features to test a sound decoder. Another use is programming a multifunction decoder prior to installation. This can be done on the workbench instead of on a layout. The tester receives DCC signals from the Track connections of the booster.
Commercial Decoder Testers
ESU 51900 Decoder Test Stand
- Five pole motor to correctly load the decoder motor outputs. Many decoders will not work if the motor load is not present.
- LED indicators for functions.
- Multiple DCC connection points.
- Speaker with impedance selection, Off,100, or 160 Ohms, as some decoders use high impedance speakers.
The ESU Decoder Tester has connections for the following decoder interfaces:
- 21 Pin MTC Connector
- Terminal Block
- NEM 651 / NMRA 6 pin DCC
- NEM 652 / NMRA 8 pin connector
- PluX22 connector (This may be missing from earlier versions)
- Next18 (May not be present).
- Auxiliary 1 to 4
May be called the LokTester V2.0
The 53901 extension for the LokSound XL v4.0/LokSound L v4.0 decoders.
For a tutorial on using this decoder, see: ESU decoder tester (Video)
The ZIMO MXTAP Decoder Test and Connector Boards for use with the MXULFA, MX10, and other ZIMO products. Can be used to update decoder software, download sound projects and testing decoders.
Most features of the ZIMO MXTAP are compatible with older ZIMO and other third-party systems and products.
- Quick Terminal Block
- Next18 (NEM661)
- 6 Pin (NEM651)
- 8 Pin (NEM652)
- PluX (NEM658)
- 21MTC (NEM660)
- 15 Function LEDs
- 5 pole Motor
- 13 x 18mm speaker
The SUSI port available on a MXULFA, MX10 and MXTAP decoder can dramatically increase uploading rates for sound files compared to standard "TRACK" connections. Automatically interfaced to the MXTAP "SUSI" port on decoders equipped with PluX, 21MTC, or Next18 interfaces, and ZIMO large scale decoders .
The "SUSI" connection for the boards are configured in parallel by using the two "SUSI" plugs to create a daisy chain allowing a user to simultaneously load sound files on multiple decoders. Each decoder must be connected to its own Decoder Test and Connector Board (MXTAP).
The LT1 is included with all Digitrax Starter Sets. It consists of a harness with 6 conductor Telco type wire and a male plug, a tester with a female 6 conductor jack and a protection resistor.
The LT1 can be used to test LocoNet cables, as well as multifunction decoders. While it is basic, it can indicate the motor control is working, as well as functions.
The LT1 uses RailSync power to check the cables. Do not leave it connected as it can destabilize your LocoNet. Cable verification is done by plugging the cable into the tester, and the other end to a Universal Panel (UP-x) to connect it to the LocoNet for power. The four LEDs should light. You must have a throttle plugged into the LocoNet when testing cables.
As the LT1 is not a LocoNet device, it should not be left connected during normal operations.
For a tutorial on using this decoder, see: Digitrax LT1 decoder tester (Video)
The Decoder Test Kit from NCE.
The DTK works with any decoder. It tests them with track power, allowing programming of a decoder before installation.
- Indicator lights for
- Motor FWD and REW
- An optional motor can be added for load testing
- F0, F0r, F1 and F2
- Motor FWD and REW
- Accessory decoders can be tested
This decoder has an 8 pin interface, which limits its usefulness.
Train Control Systems (TCS)
1595 Decoder Tester
The TCS 1595 Decoder Tester looks a lot like the ESU decoder tester, and is fully featured as well. It comes with a Kato 5 pole motor, 28mm speaker and 8 LEDs for testing functions. Power is from the track connections of your booster
The DT-AUX board adds the following connections:
Other Decoder Testers
These are no longer in production, but can be found used.
Loy's / Urlich Decoder Tester
The Loy's Toys/Urlich Models DT01 Decoder Tester includes clips to quickly connect decoder wires to an NMRA socket to test decoders with an NMRA plug. LEDs are used to indicate speed, direction, and function status. This device is assembled and ready to use - not a kit.
Build a Decoder Tester
An article also appeared the September 2001 issue of Railroad Model Craftsman regarding building a decoder tester. This issue is probably unavailable from the publisher but may be available from used book sellers.