R3890 and R3891 Class 91 Latest tooling - decoder issues

[Ollie0033]

I have purchased both of the above locos and received one of them last week . After reading the Hornby Magazine they announced that one needs to buy the R7382 21-pin decoder to ensure the loco works perfectly.

Unfortunatley Hornby forgotten to tell everybody that the decoder is not available until Summer 2023. So I have purchesed something I cannot fully use for another year - Thank you Hornby for a great job!!!!

I have tried a Hattons 21-pin decoder and the function F0,F1,F2 work okay but I cannot get F3,F21 and F22 to work. So, has anybody else tried a Hatton decoder with different functions or CV settings to get the Cab lights to work or is there another decoder out there that will support the different functions??

[96RAF]

I guess for starters you need a minimum of a 6-function decoder and that F21 and F22 would map to F3 and F4, but I am guessing without having any hard info on the new Hornby decoder to refer to.

Edit - this from Hornby

....There should be an info slip in with the Class 91 stating to check the spec of the decoder you choose to fit to make sure it works with all lighting configurations….

You need a suitable 6 function MTC decoder that supports logic level output for AUX3…..

You may also want to read this thread https://www.rmweb.co.uk/topic/150520-hornby-announce-a-re-tooled-class-91-for-2020/page/22/#comments

[Ollie0033]

Well, I can safely say there was no additional information in with the loco; There was the normal instructions and an addendum to explain function keys 1,2,3 but nothing about alternative decoders - if that had been the case I would have not raised the issue. The loco I have worked on is R3891 - I have not received R3890 yet - perhaps that will contain the illusive info.

I have read the link you put in for page 22,21,20 and 19 and can find no reference to decoder functions - is it on another page that I should try?

[96RAF]

I had not read the whole thread and assumed there would be some discussion of decoder choice to retain all lighting functions.

Given the forecast far delivery date of the Hornby decoder I fear you will have to install an alien make of decoder that provides suitable functionality.

[Brew Man]

It might be worth having a look at Digitrains' site. They have a wide choice of decoders. If you see one that you think might do, message them for verification. In my experience they are very good at responding to enquiries. Or simply message them with your requirements.

[ColinB]

It sounds like the new class 91 that you have bought needs a 4 function decoder. Trouble is a lot of the 21 pin 4 function decoders only have sufficient drive current on the lower function keys (F1 and F2) the upper two functions are logic only. I wondered why you could buy a conversion circuit on EBay for the upper two. So you need a full function 4 function decoder. I didn't realise until I read an article on it. I think Zimo and the LokSound (just decoder) plus a few others have the full four function drive

[ColinB]

Sorry in my previous post, it should read 6 function. I keep forgetting that they add the two lighting functions at F0. The bigger question is why does the class 91 need all the extra functions, I assume it is the control the lighting functions, but what are they doing controlling each light individually.

[Ollie0033]

Thanks for the replies guys - in the end I read the full thread on RMWEB and one person (Andy) had tried a Dapol Imperium since Kernow had suggested this decoder. But, he had problems with lights flickering so he tried a liasdcc decoder and he claims this works perfectly. So I have taken a risk - put an order in with Digitrains and hopefully they will arrive sometime next week - I will update this thread once I have any news ( I needed some 21-pin decoders anyhow so if they are no good for the class 91 I am sure I can find a home for them!!)

[ColinB]

There is an article about the loco in this months Hornby magazine. They explain that you need a 6 function 21 pin decoder and say that some types don't work but not why. That is a big deviation from Hornby to control all the lights, it is also not publicised in their catalogue.

[Brew Man]

I hope it works out for you.

[Ollie0033]

There is an article about the loco in this months Hornby magazine. They explain that you need a 6 function 21 pin decoder and say that some types don't work but not why. That is a big deviation from Hornby to control all the lights, it is also not publicised in their catalogue.

 

 

[Ollie0033]

There is an article about the loco in this months Hornby magazine. They explain that you need a 6 function 21 pin decoder and say that some types don't work but not why. That is a big deviation from Hornby to control all the lights, it is also not publicised in their catalogue.

I read the article which was the first warning sign that something was not right. Having said that even the Magazine did not indicate that the Hornby 21-pin would not be available for some time - they just seemed, to me, to be giving an alternative which is not the case since once has to go "foriegn" for it to work - I just wish they had indicated the decoder they used!!

[Jupiter 1707822591]

What does function 21 & 22 control ?

I can find no reference yet to these functions

[96RAF]

As Hornby have no active product, I guess it's OK to offer what the market does have available.

Zimo MX631 and 632 series cater for 6 functions in 21-pin format.

C versions are logic level output of Aux 3 and 4 and D versions are amplified output on these functions.

ESU and Zen have the same options.

Edit:

Generally, F-keys F21-F24 on these versatile decoders control Aux 1 to Aux 4 physical outputs. As we see above some are full 12v potential and some are logic level output requiring addition circuitry to operate (usually on-board the loco PCB).

[ColinB]

Thanks 96RAF I did wonder how you differentiated between the two. At the moment there seems to be a shortage of Zimo 21 pin decoders, well at least at YouChoos. I must admit I normally mail YouChoos and ask them which one they suggest.

[Ollie0033]

What does function 21 & 22 control ?

I can find no reference yet to these functions

Jupiter,

these are functions used to control the lights - I can't remember without opening up the box but F21 is headlights and cab lights and F22 is headlights, cab lights and tail lights, I think!!!

But, there is also F3 for cab lights and on the hattons decoder this does not work

[Jupiter 1707822591]

What does function 21 & 22 control ?

I can find no reference yet to these functions

Jupiter,

these are functions used to control the lights - I can't remember without opening up the box but F21 is headlights and cab lights and F22 is headlights, cab lights and tail lights, I think!!!

But, there is also F3 for cab lights and on the hattons decoder this does not work

Thanks

With a hattons decoder to get all 6 functions working CV 21 has to be 15.

[Ollie0033]

Thanks Jupiter - I didn't tryCV 21 at 15 and used the decoder elsewhere - but - today the Liasdcc decoder arrived and with this decoder I can get F1, F2, F3 working as described in the hornby instructions but I still cannot get f21 and f22 to work. (will look at cv21 for this decoder)

These extra functions are a little superflous because with f1, f2, f3 and f0 you can get all of the combinatons offered by the other functions which questions why they were every programmed? With the decoder in place tried out loco and accelaration and deacelaration needed to be slowed down and using the suggested settings from Laisdcc; the engine now works fine and shows a great full speed.

So for me problem solved I only have one issue - getting a driver in the cab seems too troublesome and delicate with lights attached to the cab - it is a pity for the sake of 10p that hornby could not have stuck one in - but that is typically hornby - no crew added!sleepy

[Jupiter 1707822591]

I think f 21 & f22 are for the hornby decoder and do not exist for the hattons or lais decoders

CV 21 does a different job on the lais it is for consist lighting .I think no alterations needed.if you do alter CV 21 the decoder reset is 4 to CV 8 .

To achieve the same functions with the hattons I think you will have to use function mapping to get an equivalent f21 & 22 light sequence .

[Ollie0033]

Thanks Jupiter. I was in contact with Digitrains today and they had a similar view. I am not going to push the issue or try anything since I have all the lighting functions I need just in a different form