Using the “Standalone” ProMiniAir Transmitter with JMRI

This post starts with some “pieces to a puzzle” before connecting them to Dead-Rail. Bear with me.

Puzzle Piece 1: The open-source and powerful JMRI software is widely used to, among other things, reprogram DCC decoders, manage locomotive rosters, and serve as a throttle and layout control agent. If you are unfamiliar with JMRI, I urge you to review the project’s web pages.

Puzzle Piece 2: The excellent open-source DCC throttle project EX-CommandStation interfaces nicely with the JMRI software via a USB cable connected to a PC running JMRI.

Puzzle Piece 3: As a low-cost dead-rail transmitter solution, I integrated the ProMiniAir Transmitter with a WiFi-equipped EX-CommandStation to provide an entirely “standalone” capability that allows the user to use Smartphone throttle apps or computer throttle apps for dead-rail control of locomotives and accessory decoders. For details, see this web page. This item is available on eBay.

The ProMiniAir Transmitter is integrated with a WiFi-equipped EX-CommandStation for a completely “standalone” transmitter solution compatible with ProMiniAir receivers, Airwire CONVRTR/G3/G4, Tam Valley Depot DRS1 receivers, and several other dead-rail receivers.

The coup de grace: When integrated with the ProMiniAir Transmitter, the EX-CommandStation allows JMRI to configure and control dead-rail locomotives or stationary decoders connected to a ProMiniAir Receiver or other compatible dead-rail receiver.

This post shows you how.


We will use an example to demonstrate the process of reconfiguring a decoder and then controlling it with the JMRI software.

The LokSound 5 XL was originally fully programmed with the LokProgrammer, including the long DCC address of 4199.

When using JMRI to configure a decoder, the “Programming On Main” option must be used. The “On Programming Track” option WILL NOT WORK.

The JMRI DecoderPro is used to select and edit the locomotive’s decoder, programmed initially with a DCC address of 2199.

Our example will be to program a change of the decoder’s Long Address from 2199 to 2196.

In this case, we are changing the DCC long address.

When a decoder’s configuration changes, it is probably best to only transmit the changes to the decoder (the “Write changes on sheet” option).

The decoder’s address has been changed to 2196. The changes are then sent to the decoder wirelessly using Programming On Main mode. No decoder response is required or feasible.

Once we exit the Programming Pane, the modified DCC address is evident.

The decoder’s address is now 2196 and should respond to throttle commands on DCC address 2196.

Let’s use the JMRI throttle or a WiFi throttle to wirelessly control the DCC decoder at the new DCC address 2196. The ProMiniAir Transmitter and a ProMiniAir Receiver handle dead-rail transmission to the decoder.

The components used in the two demonstration videos.

Now the videos. First, use the JMRI throttle.

Throttle control using the JMRI throttle.

Now use a WiFi throttle.

Throttle control using the WiFi-connected TCS UWT-50 throttle.

The following two photos provide detailed views of the Standalone ProMiniAir Transmitter integrated with a WiFi-equipped EX-CommandStation available on eBay.

Photo showing JMRI throttle connected by USB to the ProMiniAir Transmitter’s EX-CommandStation has turned power ON. Note that the PMA Transmitter’s DCC address is 9900.
The JMRI throttle sends commands to DCC address 2196, shown by the ProMiniAir Transmitter’s display. The EX-CommandStation displays WiFi information for connecting a smartphone app to the EX-CommandStation. The ProMiniAir Transmitter then re-transmits the EX-CommandStation’s DCC to the ProMiniAir Receiver connected to a LokSound 5XL decoder.


If you use JMRI to configure or control locomotive and accessory DCC decoders using the Standalone ProMiniAir integrated with a WiFi-equipped EX-CommandStation, the following aspects should be borne in mind:

  1. The PC running JMRI must be connected to the EX-CommandStation with a USB cable. JMRI provides a connection test agent to verify communication between JMRI and the EX-CommandStation is functioning.
  2. When using JMRI DecoderPro to configure or reconfigure a DCC decoder, it must be in Programming On Main mode. The EX-CommandStation is connected to the ProMiniAir Transmitter using the EX-CommandStation’s standard DCC Track Right/Track Left outputs, and using the Programming Track mode will not work.
  3. Because transmission from the ProMiniAir Transmitter to a compatible receiver, such as the ProMiniAir Receiver, etc. is one way, communication between JMRI and the dead-rail decoder is one way: from JMRI to the decoder. Decoder responses back to JMRI are not supported.
  4. Suppose you need to load sound projects or make extensive configuration changes to a DCC decoder. In that case, it’s probably best to use the manufacturer’s specialized programmer directly connected to the decoder’s DCC Track Right/Track Left inputs. For dead-rail locomotives, this is greatly facilitated by having an easily-accessible external plug directly connecting to the Track Right/Track Left decoder inputs. This plug is dual-purpose for my dead-rail installs: 1) it plugs into the DCC outputs from the ProMiniAir Receiver/Amp, or 2) it plugs into the DCC outputs of the specialized decoder programmer.

Final Thoughts

JMRI can also interface with numerous other DCC Command Stations or throttles, so if you connect the “standard” ProMiniAir Transmitter to the DCC Track Right/Left output of these devices (also available on eBay), then you will have the same capability of using JMRI to wirelessly control and configure your locomotive or stationary decoders that are connected to a ProMiniAir Receiver or other compatible receivers.

ProMiniAir Transmitter for standard DCC throttles.