ESU XL4 + Pulsed Smoke issues



26 Jan 2020
United Kingdom
Hey Maxim, fantastic work.

Given your knowledge with ESU, can you advise me please?

I am trying to test the large ESU smoke generator with an XL4 and the Lok programmer board

The programmer board isnt capable of powering the smoke unit in this setup I've discovered, so I'm using a small power switching circuit.

My question is whether the ESU software sh old switch the smoke yellow or green wire via the decoder aux terminal? I'm using yellow at the moment which I think is correct, but the smoke unit doesn't come on when the smoke function is triggered?

At the moment I have the yellow smoke wire connected to aux1 on the decoder, with smoke in f6 but f6 maps to aux2
The Aux2 function output is set to trigger the smoke chuff with aux1 set up as an ESU smoke unit

I think it may just be a case of moving the yellow wire to Aux2 for the chuff trigger, but the ESU manual shows yellow to aux1!

I'll m totally confused. Can you help?
Greg Elmassian

Greg Elmassian

8 Mar 2014
San Diego
Looking at the manual, it shows green to aux2, and the green supposedly makes a smoke burst with sound.
The manual also shows the yellow connected to aux1 also.
This is specifically for an XL v4.0, so looks like you need both.

Other installations use the susi interface.

This is from section 5.3 in the mach 2015 manual, part number 01515-16039

You also have the jumper on the smoke unit set to steam right? According to the the manual there are 3 settings of the jumper, vapor, steam, and diesel.

You have the jumper in vapor mode, and the manual does not explain well, but I think you need steam cylinder mode.



26 Jan 2020
United Kingdom
Thanks for taking time out to look Greg,

The jumper is definitely set correctly - the steam cylinder' mode as they term it, is used if you decide to go with an optional maniflold in ordet to channel the snoke output down to the cylinders. 'Vapor' as they term it, refers to smoke stack output.

Something which doesn't help in their manual is an error in the wiring diagram for rthe XL. The harness on the smoke unit is
which marries up to figures 2 and 4 in the manual, so I'm happy
Green = chuff trigger
Yellow = Aux1
Red = power
Blue = SUSI clock (unused in this setup)
Grey = SUSI data (unused in this setup)
Black = Gnd
On the all important figure 6, they show the colour sequence on the header wrong; yellow,green,red...
However yellow *is* shown as going to Aux1 onthe decoder. (On that basis I think they just show the colour order at the smoke unit end incorrectly in the picture)

In the decoder output programming
Yellow/Aux1 is set to smoke unit (so I think that'd be the heater on/off logic)
Green/Aux2 is set as you say to the steam burst (so, I think that'd be the fan control)

I think I probably don't have the power switching circuit hooked up correctly. The circuit I am using it this one - proven to power the ESU smoke unit with the ESU decoder tester board (note that horrific-looking last picture isn't mine - I breadboarded it! :) )