ESU Decoder Tester and the secret blue wire....

[gordon s]

I've been using an ESU decoder Tester for a couple of days now, but there's something I don't understand....

 

Plugged several decoders in, mostly new to test and they all seem to do what they are supposed to do. The lights come on for the motor direction and directional lights. F0 and F1 led light up for on and off, but no lights come on at all for F2, F3 and F4 etc on any of the decoders.

 

Am I missing something or just misunderstanding what it should be doing? Tried searching the web, but nothing has come up yet...

Edited April 15, 2020 by gordon s

[JimFin]

Depends on the default values of the decoder you are looking at. F2 is often a push and hold function to sound a horn so unlikely the tester would illuminate, F3 onwards can be defined in many ways. Check the manual for the decoder for details, they may not have a value until you set one.

[gordon s]

Thanks Jim.

 

I wasn't 100% sure what I needed to do so reset each decoder to factory defaults and thought that would do the trick. Tried different values with my Zimo MX600R as per the chart on page 26 and 27. As a relative newcomer to CV's, I'm still finding my way and the notes in the Zimo manual are a little confusing. 

 

When I've fitted decoders to US loco's before, I've just plugged a decoder into the 8 pin socket and the bell, horn, lights etc just worked. I thought that switching F2 etc at the programming stage would just illuminate the corresponding led on the tester. 

 

http://www.zimo.at/web2010/documents/MX-KleineDecoder_E.pdf

 

From the Zimo manual, are you able to give me some pointers as to what needs to be done?
 

Will other manufacturers decoders require different values?

Edited April 14, 2020 by gordon s

[Nigelcliffe]

You said the words "eight pin".   An eight pin socket has three functions on it - Front Lights, Rear Lights, and Aux1 (or whatever the maker chooses to call the third output).   The remaining five pins being "pickups (2)", "motor (2)" and "common positive blue".   

 

Any other outputs are either loose wires which have to be connected, or solder pads which needs soldering, or not present.  

The MX600 has four functions in hardware, so that's one wire connection to make over the connections on the eight-pin socket.    If you want more functions (say six or ten), then you need a different decoder from the Zimo product range.

 

 

 

The larger pin count sockets, such as 21Pin or PluX, or Next18 will have more function outputs connected through the socket.   

 

 

 

 

- Nigel

Edited April 14, 2020 by Nigelcliffe

[pauliebanger]

Most non-sound decoders are supplied with NMRA function mapping as default.

 

That is, headlights front/rear directionally on F key 0, Function Output 1 (FO1, a.k.a Aux1) on F key 1. FO2 on Fkey 2, FO3 on F key 3 and so on.

 

So, the mapping of functions to operating keys is more or less standard (for non-sound decoders only).

 

The issue of 'latching' or 'momentary' action of any individual F key is determined by your controller's abilities. Many US designs have almost all F keys as latching. Most European designs are much less restrictive by allowing any F key to be assigned as either latching or momentary (and to be different for different models) as you wish.

 

I suspect that none of the above are the cause of your non illuminating Tester LEDs, and Nigel's post (made whilst I was typing this) explains why if you are using 8 pin decoders.

 

If you are using 21 pin decoders, there is a futher complication. The ESU decoder tester is designed for ESU decoders, though others can be accomodated with some provisos. ESU 21 pin MTC decoders have only logic level outputs on AUX 3 and above, and the test board 21 pin socket is wired to anticipate this, as you would expect.

 

Many other brands of 21 pin decoder, including most ZIMO*, have Open Collector** type Function Outputs on FO3 and above  (**a.k.a. 'full power' or 'normal'). The ESU tester will not operate the LEDS correctly unless the decoder has Logic Level only FOs on Aux3 or above.

 

*ZIMO make a variation on the MX644D 21 pin sound decoder (MX644C) which has logic level on FOs 3 and 4, so will illuminate the relevant LEDs on the ESU tester board. The non-sound equivalent, MX634, has Open Collector on FOs 3 and 4 by default but can be changed by CV to have Logic Level on these FOs instead.

 

ZIMO's own decoder tester, MXTAPV, has 13 LEDs (to cope with the higher number of standard-issue FOs on some ZIMO decoders). It also has a jumper to change from testing Open Collector to Logic Level if you need to, so can be used with 21 pin decoders of any flavour and get reliable LED indication of FO functionality.

 

Best regards,

 

Paul

[gordon s]

Thanks guys, that now makes sense.
 

I hadn’t counted front and rear light as functions when used in an 8 pin decoder. In reality all the decoders I have used in the past have been 8 pin devices and in my head four functions meant F1,F2,F3 and F4 in addition to the front and rear lights. It’s all starting to make sense now, so thanks for taking the time to write replies.

 

I’d also overlooked that as most of my loco’s are steam, it’s second nature for me to heat shrink the other five wires as they aren’t needed and of course they weren’t connected to the tester......Doh!

 

Still much to learn.....

Edited April 14, 2020 by gordon s

[pauliebanger]

And so much time now to do so. LOL

 

Actually, just to put things into perspective for you, I've been following your DMU lighting posts, under the masterful eye of Nigel.

 

I have several different classes of 1st gen DMUs fitted with ZIMO sound decoders with my own sound projects but I've always been disappointed that they did not make the various internal and external lights independently controllable, thereby wasting the wealth of FOs available. Of course, I've done nothing about that, yet.

 

Your recent exploits have reminded me of this and your dismantling/investigations of your models looks as if it might be very helpful. 

 

Thanks to you and to Nigel for doing the spade work; based on this, I intend to improve my models - when I get a minute. (Only drawback is that I'm part-way through a change to 0 Gauge and have nowhere to run 00 gauge now).

 

So, even for someone who has not operated a DC layout since 1979 (Zero1 until DCC arrived) there's always something to learn.

 

Best regards,

 

Paul

[gordon s]

Thanks Paul, even though I’ve been playing trains for years, there is so much to learn.
 

That’s one of reasons I find RMweb such an invaluable resource. We all know bits about something, but none of us know everything about everything. Passing on those odd scraps of information can often make difficult issues simple to follow.

 

My fun with the Derby Lightweight was spread over several days, but in reality the whole job could be done in an hour or so, once you know where to cut and what wire and resistor goes where. Most of the time was me tracing connections with a multimeter just to understand the circuit.

 

I couldn’t have done that without Nigel’s assistance, so if it helps others deal with the same issue, then it was all worthwhile.

[Nigelcliffe]

From my side, half the interest is puzzling out how the loco/carriage might have been constructed, without one in my hand.  And trying to do a bit of informal teaching along the way.     Most things people want in their models are possible, its just working out how to get to a satisfactory conclusion. 

 

Its also a change from weeding the garden. 

 

 

- Nigel

 

 

[gordon s]

Tis me again....

 

I have a box with several discarded decoders, so thought I would test them and throw away the duff 'uns. Nearly all of these are wires only, so started connecting the wires via the terminal block.

 

Most of it is self explanatory other than the blue wire or common. The manual is a bit short of info, so I have no idea what the blue wire is connected to.

 

I've looked for a +24v or U+, pos terminal and can't see one anywhere.

 

What makes it even worse is the manual for the 53900 shows the earlier model.

 

 

This is the one I have and no sign of where to connect the blue. They also talk about purple for AUX 2 whereas Zimo have a brown wire labelled Function Output 2. I assume they are the same.

 

I feel this is like a where's Wally comp and I can't see him.....

 

 

Perhaps this is a secret only known to DCC experts.........Come on, let me in.....

 

 

 

Edit: OK took a flyer and connected brown to Aux 2 and left the blue wire disconnected. It seems to work, so is there no need to connect the blue wire at all?

 

I have to say the manual is confusing, particularly showing the earlier model in the connection diagram.

 

 

Edited April 15, 2020 by gordon s
Continued testing....

[Nigelcliffe]

Blue is mostly "optional" on decoder wiring into a loco.   So, it appears to be not needed on the tester.

 

There are two ways of getting a postitive for the circuit from function outputs.   One is the blue (common positive),  the other is to use one of the pickups, which will give a half-wave response.   As the DCC frequency is kHz, it shouldn't appear as flickering, though tiny capacitors are sometimes added to lighting circuits to remove any flicker.   (A variant on the "pickup" is to use both of them, with appropriate diodes in place, and the power is then exactly the same as the common positive which comes via the equivalent diodes on the decoder itself.  ). 

 

 

 

- Nigel

 

[gordon s]

Thanks again Nigel. Where would we be without you?......

[pauliebanger]

The wiring colour difference arises because the NMRA specifies for FO2, either brown or purple. Most brands use purple, but ZIMO uses brown.

 

When it  comes to sound decoders, that means ZIMO uses purple for the speaker wires whilst others use brown.

 

It's as well to remember to describe the function of wires in any posting  rather than relying just on colours, since 'coding' is not universal. (And some model manufacturers appear to have never understood the principle).

 

Best regards,

 

Paul

[Kubel82]

Sorry guys, but like Gordon S, I too have a 53900 and find the so called ESU Tester 'Instructional Manual' totally inadequate for a novice.

 

I am running an N Gauge layout with Lenz controller and various decoders. 

 

One of my Farish locos has a suspect Hornby TTS sound conversion which is intermittent.  I have connected the decoder wires to the Tester.

I too have a mysterious blue wire off my Hornby TTS decoder with nothing to connect it to.

 

My 'simple' questions are  ( Yes/No answer will suffice)

 

1.  Can I connect a non-ESU decoder, such as a Hornby TTS and get a sensible fault diagnosis from the Tester?

2.  What is the issue with FL LED showing flashing yellow in one direction and

 RL Flashing Red in the other direction?  Is this the same warning that you get from a Lenz decoder showing a short circuit by flashing the loco lights on and off at Zero throttle position?

3.  Is the speaker polarity important?

4.  Could the flashing LEDS be rectified by connecting the blue wire somewhere?

 

Can I make my ESU Tester a 'Universal' device for various manufacturers eg Youchoos Zimo, or do I bin it as too ESU specific?

 

Thanks

 

Keith

[Kubel82]

I know it works with Lenz decoders.

[John ks]

3 hours ago, Kubel82 said:

1.  Can I connect a non-ESU decoder, such as a Hornby TTS and get a sensible fault diagnosis from the Tester?

Short answer   

yes

Longer answer 

The decoder tester is a virtual loco, in that it has all the electrical components found in a loco IE. motor, lights & speaker , so yes

 

 

How you connect the tester may make a difference as to which decoders can be checked

EG if you connect to your DCC programming track then it is limited to that DCC system's capability

It can be connected to a computer(running JMRI decoder pro) through a Sprog then programming is limited to the capability of JMRI

It could be connected to a computer(running LokProgrammer) using a LokProgrammer, my understanding is this setup works best with ESU decoders

Sorry if i got a bit longwinded 

3 hours ago, Kubel82 said:

3.  Is the speaker polarity important?

Short answer No

 

If you are using multiple speakers than the polarity of one speaker to the other is important but the connection of the group of speakers to the decoder is not

 

Regarding the other questions , i don't know

John

[Kubel82]

Thanks John.  Crystal clear mate.  Thank you for getting the discussion under way.  Not a bit longwinded.  :-)

 

Keith

[Nigelcliffe]

12 hours ago, Kubel82 said:

Sorry guys, but like Gordon S, I too have a 53900 and find the so called ESU Tester 'Instructional Manual' totally inadequate for a novice.

 

I am running an N Gauge layout with Lenz controller and various decoders. 

 

One of my Farish locos has a suspect Hornby TTS sound conversion which is intermittent.  I have connected the decoder wires to the Tester.

I too have a mysterious blue wire off my Hornby TTS decoder with nothing to connect it to.

 

My 'simple' questions are  ( Yes/No answer will suffice)

 

1.  Can I connect a non-ESU decoder, such as a Hornby TTS and get a sensible fault diagnosis from the Tester?

2.  What is the issue with FL LED showing flashing yellow in one direction and

 RL Flashing Red in the other direction?  Is this the same warning that you get from a Lenz decoder showing a short circuit by flashing the loco lights on and off at Zero throttle position?

3.  Is the speaker polarity important?

4.  Could the flashing LEDS be rectified by connecting the blue wire somewhere?

 

Can I make my ESU Tester a 'Universal' device for various manufacturers eg Youchoos Zimo, or do I bin it as too ESU specific?

 

Thanks

 

Keith

 

I think the question and terminology (eg "fault diagnosis") suggests a misunderstanding of the ESU device.   It isn't a "tester" in the sense that it will produce any diagnostics of decoder faults.   Instead its a "static bench locomotive", which allows you to see that all decoder functions are working as anticipated with the decoder not fitted to a locomotive.

 

Question answers

1 - any decoder will work, you'll get exactly the same information from using the device regardless of decoder fitted. 

 

2 -  Two guesses:   
      a)   speed step mis-match.  What are the settings in the decoder for speed steps, and what speed steps are in use on the throttle ?  The latter will be a setting in whatever DCC system is powering the ESU device.    If they don't match, then some combinations will lead to flashing lights.    

      b )   something around the decoder expecting the lights to have a smoothing capacitor on them in the loco.   (I would expect this to be a fairly high frequency flashing, see (4) below ).  

   And no, its not the TTS decoder reporting an error.   The use of lights for error reporting is specific to certain decoder makers, Lenz being one of them.   If the decoder maker doesn't say this happens, then it doesn't happen.    And NOTHING to do with the ESU device. 

 

3 -  not important for one speaker.  Does matter for sound quality (but not electrics) for multiple speakers, where the phase of speaker cone movement makes a difference to the sound (ie. both moving inwards together, or one going in, the other out at the same time).  

 

4  -   the blue wire is the decoder common positive, used in some wiring arrangements to provide the positive supply to lights (the other wire being one of the function output wires, typically white, yellow, etc..).   It is not needed in the ESU device because the LEDs receive their positive from one of the track feed wires.   This is how a N gauge 6-pin decoder works, and is another wiring option for just about any DCC decoder.   The LEDs wired this way receive half-wave power, so might be flickering at a high frequency.   

 

The ESU device is as "universal" as anything else.   As said above, its a "static bench loco".  Its use as a tester requires the operator observe the outputs (motor, sound, lights) and perform their own diagnostics based on what is seen in combination with the throttle settings and what parameters are set in CVs in the decoder.    Using it with just a throttle will be long-winded to do much beyond very basic tasks, as noting down all CV settings manually gets somewhat tedious.  This is where computer software makes life easier.    

 

 

- Nigel

 

[Kubel82]

Brilliant Nigel.  Thank you too.  :-).  Keith