Multimaus and Decoder Issue

[murray1]

I run my layout with a Roco Multimaus controller. Recently bought a Hornby  R8249 decoder and cannot manage to get to run a selection of Hornby DCC ready locos.

Any advice if there is a compatability issue between the controller and chip, or is there any CV adjustment I can make to the CVs.

 

[34theletterbetweenB&D]

A little more information is necessary. Have you been able to read the decoder default address with it installed on any of the locos you have tried it with? If so have you been able to perform an address change?

 

 

[melmerby]

Exactly what is meant by a Roco Multimaus?

I have one of these and it is just the handset.

[murray1]

Once fitted the decoder and placed on the track it run uncontrollably with no control from the handset. Same for three DCC ready Hornby Railroad engines. Controller is the Roco complete system. Cannot read back with the Multimaus so looking to simply programme. Already fitted 4 TTS sound decoders with no problems.

Edited October 17, 2019 by murray1

[34theletterbetweenB&D]

Same uncontrollable 'runaway' on three different mechanisms makes it likely that the decoder is simply a dud, return for exchange.

[murray1]

Had already sent 1 back to shop who sent replacement which is exactly the same. That's what made me think I was setting up wrong. 

[Guest JiLo]

I have a Roco z21 system and it doesn't like Hornby decoders at all, all other makes are fine

 

Best replace with another manufacturers products

[murray1]

I fear that is the case for me. Doesn't explain why the TTS decoders are all fine. 

[melmerby]

The Hornby R8249 is IMHO the decoder not to buy as it has a poor specification but isn't even a particularly cheap decoder.

Plenty of better choices e.g here:  Lenz Standard +

Streets ahead value wise

Edited October 17, 2019 by melmerby

[RexAshton]

If I'm looking for a reliable cost effective decoder my first choice is DCC Concepts Zen range. I use a Multimaus and have never had a problem them.

[Butler Henderson]

Whilst the Hornby R8249 (and its 6 pin and comical 4 pin variants) is one of the worse decoders on the market the issue might the high voltage the Roco transformer puts out; substituting it with a laptop power supply might resolve the issue. Have a number of Hornby Sapphires picked up cheap in toy shop etc sales and not had any problems with them .

Edited October 17, 2019 by Butler Henderson

[murray1]

Were/are  you using a Multimaus.  I did wonder about the high voltage. I will check but beleived my transformer was actually reduced already.  Tried to change CV29 to value 2 to eliminate it possibly running on DC. Looking to replace decoder for a better one. Thank You all.  

[melmerby]

16 hours ago, Butler Henderson said:

 Have a number of Hornby Sapphires picked up cheap in toy shop etc sales and not had any problems with them .

However at normal price you are well out of the budget price decoder market which would still throw up better choices.

[Butler Henderson]

Woudn't touch a Sapphire at "normal price" - all mine were acquired for well less than half price and some were less than £10

[Suzie]

If your Multimaus has the small DC power supply (as shown in the photo above) you should be OK, but if you have the big transformer instead that was supplied previously the voltage is likely to be a bit high (19V+) for some of the poor quality decoders which do not meet NMRA spec.

 

In reality the decoders should work, so send the faulty ones back for a refund and buy Zimo - you just can't go wrong with Zimo decoders and the new entry level range are excellent value at £20 or less.

[Phil S]

As Suzie has said.... The switched mode power supply shown produces a stable 18Vdc into the Multimaus's Amplifier which produces a stable 16Vdcc track voltage which is within spec AND the Hornby decoders spec.  The multimaus/ amplifier combination also produces a good output waveform which should have no problems being read by the Hornby decoder.   It is basically ... Apparently ... The same as the loco driving part of the TTS decoder.  ( spec for the TTS confirms 22_23v rating )   the multimaus does not produce the ringing that a Select does.

 

If your locos were numbered 100-127 then the multimaus, on its own, expects them to be a long address ....... Although when used with az21 this can now be a short address.

 

The multimaus and TTS combination was one that experienced the 180 degree physical rotation problem.  .... Cured by sending the decoders back to Hornby for reprogramming.   This has not affected the silent version as far as I am aware.

 

I also assume that the basic Hornby decoder original release is not the one being referred to as this only had short addressing and kept losing its address when ever a short occurred on the track. ( I think that had a different number )

 

You appear to say you are testing a single Hornby decoder and trying it in several different Hornby DCC ready locos:  so not surprising that the same behaviour shows on each...

 

The wiring of some Hornby locos, from the factory, has been known to blow decoders because the wires from the track went to the track AND motor socket pins .... Which does not show up when testing on analogue !! ....it does when you check from each wheel to the socket, with blanking plug removed.

 

Pin 1 has also sometimes been wired 180 out ..Hornby are not alone in this production error but it is not 'fatal' when there is no lighting connection.  Early class 50s blew decoders.

 

The Hornby decoder is only rated for 0.5amp .... 

But this should be okay for DCC ready Hornby locos.

 

Do you have anything else you can test the decoder in?? Eg the ESU testbed, or one of your other, known working locos that tales only 0.5 A or less.

 

 

The Red Roco multimaus can only read back when used with the Rocomotion interface, multicentrale pro, or z21.  .... Readback only slows down writing !!

 

It is not necessary to read any CV to write to it.    If in doubt there is reset with (usually cv8=8)   or simply writing the desired value which is very easy with the multimaus even if you don't use the shortcut keys. ( I never do ... I always go into the menu ... Shortening its access time to 1 second.                   It DOES, however, still ensure the current drawn when programming is within range ... Or gives an error code.

 

Remember also that the multimaus remembers the last speed etc of about the last 32 locos and so if you last used loco X and deselected or turned it off with a non zero speed,  the next time that loco is placed on the track, it will go off at that speed.

 

Cv5 max speed is not adjustable on the basic or TTS decoders.

 

You / other potential multimaus users may find the following of interest:

Despite the manual saying 'cv1'  for the 64 library (named) locos, they can be any mix of long and short addresses.  Library also remembers the 14 28 or 128 speed setting for each loco in the library. ( but this is overridden when Rocomotion/RrandCo is on line ). 5 characters or 10 with z,21.

 

The Amplifier shown can alternatively be used as a booster ( so having 2 or more  from starter sets can be useful ) ....  To use as a booster simply DO NOT insert any controller into either Master or Slave sockets. The Booster socket is a passive loop through ....  When sold as a booster, the second socket is installed, and the master+slave sockets omitted.  You can either add the 2nd socket ( soldering needed ) OR simply use an external Y splitter.

 

Anyone using their multimaus with the old transformed will find their track voltage can reach the maximum of 21-22V ** when no loco is running because it is not regulated ....unlike the modern energy efficient SMPS supplied ( which are 18Vdc)

A laptop brick of 18 V DC / 3.5A ideal.

 

** This shows up with coach lighting: bulbs can melt plastic and  LEDs too can be overrun ...remember they are nonlinear and, for example, a 12Vdc led lighting strip of 20mA per 5cm can double to 40mA at 14V

Edited October 19, 2019 by Phil S

[murray1]

 Cheers Phil - a lot of useful information on the Multimaus. Happy with the power supply and will possibly return the decoder. Unsure if it is likely to have 2 consecutive faulty items though. No issues with retailer as they have already supplied a replacement. 

[melmerby]

9 hours ago, Phil S said:

  It is basically ... Apparently ... The same as the loco driving part of the TTS decoder.  ( spec for the TTS confirms 22_23v rating )  

That would account for the near identical speed abberations then.

 

9 hours ago, Phil S said:

I also assume that the basic Hornby decoder original release is not the one being referred to as this only had short addressing and kept losing its address when ever a short occurred on the track. ( I think that had a different number)

That was R8215 which wouldn't even work properly with many basic DCC systems.*

I had two Hornby DCC fitted locos with these decoders and I can't understand why they ever saw the light of day as they didn't even reach the basic requirements of a DCC decoder.

 

* wouldn't work on my Lenz system or the shop's EZ Command.

Edited October 20, 2019 by melmerby

[Phil S]

3 hours ago, melmerby said:

That was R8215 which wouldn't even work properly with many basic DCC systems.*

I had two Hornby DCC fitted locos with these decoders and I can't understand why they ever saw the light of day as they didn't even reach the basic requirements of a DCC decoder.

 

* wouldn't work on my Lenz system or the shop's EZ Command.

I bought a batch of 10x  (8215) on their initial release 8-(.  A fundamental marketing error (still partially true on current packaging) ... they initially claimed 256 adresses instead of 127 and they still claim it uses Xpressnet .... which is true only for the Select, Elite and Elink controllers ... NOT any of the decoders loco or accessory etc. .. written by marketing with no understanding on all of the digital products

 

I waited until they released the more compliant version before sending 6 back for replacement as they failed to meet their declared spec and were unfit for purpose ... I would have sent the others back back had given 1 away and either forgotten what i had put them in or only used them for directional lighting effects using 1_99. 
 

Howevet, i still find it odd that (a current version )  does not appear to work .. unless there is some other cause if it hascbeen more than one ....and a replacement has already occured...   so i would want to thoroughly check the first loco used each time, with a meter, and or prefereably tested in a known good loco. 

 

What locos were used ????

 

That said, i would not jormally purchase more of them  ... i have bought a box  a while back because, at the time, they were still economical and small ... i fitted them into tram conversions (under the stairs) .  the stiff wires used are a fragility problem. ... but in some of my uses i only wanted the 4 wires, and that version of the decoder WAS cheaper still. i have rewired several as a result.  At the time 4_wire version was10gbp. or lenz std v2. 13-15gbp direct from germany.

 

Current Multimaus software for 29 functions (lights + 1-28) is 1.05  see Roco.cc ... Service ... Downloads.   or via  z21.eu for information.

upgrading is by connecting to either a multi centrale pro or Z21 family.

Edited October 20, 2019 by Phil S
added multimaus software versions and loco type request

[melmerby]

On inspection the R8215 and R8249 look incredibly similar

Hornby seemed to class them with a blob of coloured paint as if they might be the same decoder with different firmware blown into the PIC.

Edited October 20, 2019 by melmerby

[murray1]

Update - I have purchased a Howes Loksound class 108 sound chip. This also shorts the control system when place on track. So not just the Hornby R8249 and proves that decoder was not the issue. Replaced the supplied power supply with a variable voltage laptop power supply with 3.5 - 4amp supply. Hoping this would help. I have an electrofrog point in a yard providing two sidings. Can that make a difference. What really confuses me is that my 5 Hornby TTS engines all run and perform perfectly. 

 

Any suggestions as to how I can get the non-TTS engines running. Worried I will permanently damage the expensive full Sound chips. 

[Phil S]

Have you any 'safe' means of connecting these decoders to the controller output without either tbe loco or the track ?  ( without risk of accidentally shorting track-to-motorconnections )  I assume you do not wish to cut off any supplied plug 8-)

 

A relatively safe test should be to try powering them with a 9Vdc battery ... in or out of the loco.  with that, you should also be able to measure the current being taken .... with just a speaker  and/or a  motor [motor resistance more than 20 ohms ... nearer 30 preferably]

 

Without power applied, a resistance measurement would be 'about half scale' on an analogue meter, and  something like 1000-1500 ohms when measuring just the decoder inputs ( a diode bridge = the input)

 

When you DO get to test the loksound ... don't forget that there will be a delay between telling it to move, and the motor turning, when the sound is 'on' to match the sound sequence.  with sound off this should start almost immediately  

[ 7 seconds on some of the Hornby TTS chips ]

 

on one of the Bachmann 2-decoder dmus I have found signs of a factory correction to the pcb correcting a 'mirror image' of the 8 pin socket.   i can't recall which type. Errors marking pin1 have also occured in models  such that the blue+ is misconnected. but I think these were errors in the trailer car.

 

 

 

 

 

 

 

Edited October 29, 2019 by Phil S
added possible 108 errors

[murray1]

Thanks Phil - not really got the opportunity to only test the decoder. Just puzzled as to why the TTS are good. 

[murray1]

Thanks for the information. I removed the Howes sound chip and fitted into a Hornby DCC class 55 chassis. Pleased to say the decoder performed perfectly sounds all good, so no damage to that one. 

The problem as suggested (many thanks) appears to be the socket on the Class 101. Can I ask if these can be replaced / repaired if faulty. I would prefer to have this done professionally as the risk of blowing full sound chips is too high.

The basic Hornby decoder that I believe is blown totally as didn't work in the Class 55 chassis I will just bin as has been suggested wasn't probably the best buy in the first place. 

[RFS]

9 minutes ago, murray1 said:

Thanks for the information. I removed the Howes sound chip and fitted into a Hornby DCC class 55 chassis. Pleased to say the decoder performed perfectly sounds all good, so no damage to that one. 

The problem as suggested (many thanks) appears to be the socket on the Class 101. Can I ask if these can be replaced / repaired if faulty. I would prefer to have this done professionally as the risk of blowing full sound chips is too high.

The basic Hornby decoder that I believe is blown totally as didn't work in the Class 55 chassis I will just bin as has been suggested wasn't probably the best buy in the first place. 

 

As it's clearly a manufacturing fault I think you will find Hornby will do it for you f.o.c. Worth giving them a call in the first instance. If they agree to take it on, I would also send them the failed decoder as they may well replace it for you given that it was their fault it blew in the first place ….