Dapol Class 68 OO with Zimo MX644D - what you need to know

[John YouChoos]

For those wishing to fit a Zimo sound decoder to their new Dapol OO Class 68 model, here are some pointers that you'll need to be aware of.  Certainly this is what I found doing an install on a ScotRail one today...

 

It seems that the wiring of the circuit board has been bodged to work with the logic-level 5th and 6th outputs of the standard LokSound V4, but because the Zimo MX644D provides full-power 5th and 6th outputs (actually it has 8 full-power outputs!), the halo lights of the 68 don't work out-of-the-box.

 

Firstly, a thin enamel bodge wire has been added to bridge the GND pin with both halo circuit lines, and this should be removed.  See the thin copper-coloured strand-wire marked below:

 

 

Next, add a wire from the 5th output pin to the resistor for the front halo light (it is one that eventually goes to a fine black wire on the model):

 

Next add a wire from the 6th output pin to the halo resistor at the rear end:

 

That's it!  I discovered that the diodes on those routes were the wrong way round on my model too, or simply not soldered in properly (might have been a deliberate approach due to the bodge wire that was added), so it would never have worked the halos, but no worries, as the bridge wires we just added bypass the diodes anyway.

 

Here is the result, first with the body off:

1) close-up of the circuit board, all lights off

2) white headlights on (no halo)

3) red lights on

4) white headlight AND halo on now (halo is the top one of the 2 white LEDs)

 

Now with body on, you can actually see the halo effect, which is pretty neat - like angel eyes on BMWs!  This approach gives you independent control of the halos and the headlights:

1) no lights

2) just the headlights

3) just the halos

4) both headlights and halos

 

I've updated my YouChoos template project for the Class 68 so that you get full control of these on suitable Function Keys, so all you have to do is the above steps, plug in the decoder and speaker (Dumbo LS55X22X09-2W dual) and off you go.  Really pleased with this sound project too, and with that big speaker, it just burbles perfectly!

 

Hope that's useful for Zimo fans.

John

(YouChoos)

 

[NaN]

Hi John

 

Thanks for that. I was trying earlier with the non-sound 634D version. Reading the Zimo manual of mentions CV8 swapping the functions between logic and normal. Would that achieve the same outcome as your change in wiring? Or in other words, make the chip act in the same way as the Loksound

 

Thanks

[John YouChoos]

Hi John

 

Thanks for that. I was trying earlier with the non-sound 634D version. Reading the Zimo manual of mentions CV8 swapping the functions between logic and normal. Would that achieve the same outcome as your change in wiring? Or in other words, make the chip act in the same way as the Loksound

 

Thanks

No, I suspect not.  I think what Dapol have done is for the 68s that are shipped as NOT DCC FITTED, they have done some mods to the circuit board which make the halos unreachable completely.

I think you'll have to remove the enamel wire regardless, and either re-seat the bodged diodes to work in the right direction, or simply bypass them with a bridge wire like I did.

I haven't seen a factory DCC FITTED or SOUND FITTED model, but I have a sneaky feeling that the DC ones have been bodge in the same way as the one in my example.

 

I'm not convinced that the logic-level outputs has anything to do with it on second inspection.

[pauliebanger]

I can't comment on the Dapol 'modifications' personally, but if set up correctly for Loksound V4 21MTC, then the MX644D is not correct as it is not an MTC compatible decoder.

 

ZIMO manufacture a 21MTC compatible decoder, MX644C which has logic level outputs on Aux 3 and 4 the same as a Loksound V4 21MTC so should be compatible. There is a choice of non-sound, either MX632C or MX634C.

 

Using PluX decoders would stop all these incompatibility problems which arise with 21 MTC decoders, but ZIMO has such a wide range of decoder types available to choose from that it would be difficult to find a situation where it's not possible to find a suitable configuration.

 

Just need to select the correct hardware version.

 

Kind regards,

 

Paul

[NaN]

I can't comment on the Dapol 'modifications' personally, but if set up correctly for Loksound V4 21MTC, then the MX644D is not correct as it is not an MTC compatible decoder.

 

ZIMO manufacture a 21MTC compatible decoder, MX644C which has logic level outputs on Aux 3 and 4 the same as a Loksound V4 21MTC so should be compatible. There is a choice of non-sound, either MX632C or MX634C.

 

Using PluX decoders would stop all these incompatibility problems which arise with 21 MTC decoders, but ZIMO has such a wide range of decoder types available to choose from that it would be difficult to find a situation where it's not possible to find a suitable configuration.

 

Just need to select the correct hardware version.

 

Kind regards,

 

Paul

Hi Paul

 

The 634D is 21 pin MTC. The Zimo Manual (page 7) seems to state that it is simply a CV(8) change to make the D a C version. Based on what you've said above that would make the Halos work? I would try it but I don't have access at home to a DCC controller.

[pauliebanger]

Hi Paul

 

The 634D is 21 pin MTC. The Zimo Manual (page 7) seems to state that it is simply a CV(8) change to make the D a C version. Based on what you've said above that would make the Halos work? I would try it but I don't have access at home to a DCC controller.

 

Yes, you are right. Thanks for raising the point.

 

I don't use non-sound decoders very often and had forgotten that the MX634 21 pin could be converted from a 'D' (All Function Outputs 'Open Collector') to a 'C' (Logic Level on Aux 3 and 4).

 

Another example of progressive thinking by ZIMO.

 

This being the case for this particular decoder type, pseudo programming of CV8 to 3 will result in 'Logic Level' outputs on Aux 3 and 4. This should allow the Halo lights to operate as designed by Dapol.

 

This ability to change between C and D types does not yet apply to MX644D, but there is a separate MX644C available which has Logic Level on Aux 3 and 4 (I've got some).

 

I can't test or verify this as:

 

I don't have a Dapol 68, my DCC equipment is at the Lincoln show on my demo stand for the weekend, and I don't have an MX634 to hand.

 

Let us know how you get on, please.

 

Kind regards,

 

Paul

[spice1977]

Thanks to John for this and for emailing me the updated CV values. All done, took all of five minutes and now have fully working halo lights with a Zimo MX644d. Now wheres that factory fitted sound one? 

[Nikabd]

Hi,

 

I am new to this forum and only started using it to get help with programming Zimo decoders which I'm not as familiar as ESU Loksound/lokpilot.

Thanks a lot John for pointing out regarding the bridge wire on Dapol Class 68 board. I spent the whole weekend trying to activate aux 3 and 4 but to no avail until I read your advice.

 

I used Zimo MX643D non sound decoder. I followed the instruction as described by Paul in his previous answer to a query about Zimo MX643P22 factory equipped decoder on Roco locomotive such as Class 460 Migros SBB. As suggested by NaN, to consider converting MX643D to MX643C. I am very pleased to inform you all that the Halo light works in both direction. So no need to cut the bridge wire. I may use John's method should I decide to use

AUx 5 and 6 in future.

 

Here are my steps:

1. CV8=3 to convert the amplified output to logic output. I think Dapol purposely provide an amplified output for (aux 3 and 4) to cater for ESU decoders which makes sense but I wish they could give information about this issue. What I don't know if this will also convert aux 5 and 6 to logic output on MX643D (not C)

2. CV61=97 which is an alternative function mapping without left shift.

3. Change CV37 to 48 to 0. I did not alter setting for CV33 to 36 to keep F1 and F2 keys as default for rear white headlight and rear tail red light.

4. CV129=1 to active aux 3 for front direction.

5. CV130=2 to activate aux4 for the reverse direction

6. CV430=3, CV432=3 and CV434=0. To use F3 key to activate the Halo lamp in forward direction.

7. CV436=4, CV438=0 and CV440=4. To use F4 key to activate the Halo lamp in reverse direction.

That's it.

 

I found Zimo manual is too comprehensive and complex. To some extent this also applies to ESU as well. I wished they would give basic instruction as described above for the novice like me.

For the Zimo MX643P22, I wired to the base of the 21pin on the circuit board for aux 6 and 7 as well as common +ve to use for cablight and veissman coupler.

Like Dapol, Jaegernddorfer also has amplified outputs for aux 3 (probably for aux 4) on its new Taurus locomotive. Again I presume they cater for ESU decoders. I had been struggling trying to activate the coach lightings for Jaegerndorfer Railjet coaches until I read NaN's suggestion.

 

Thanks for your help guys. I hope this information will help other Zimo fans.

 

Kind regards

Nik

 

Photo showing Class 68 with Halo light on

 

[NaN]

Yes, you are right. Thanks for raising the point.

 

I don't use non-sound decoders very often and had forgotten that the MX634 21 pin could be converted from a 'D' (All Function Outputs 'Open Collector') to a 'C' (Logic Level on Aux 3 and 4).

 

Another example of progressive thinking by ZIMO.

 

This being the case for this particular decoder type, pseudo programming of CV8 to 3 will result in 'Logic Level' outputs on Aux 3 and 4. This should allow the Halo lights to operate as designed by Dapol.

 

This ability to change between C and D types does not yet apply to MX644D, but there is a separate MX644C available which has Logic Level on Aux 3 and 4 (I've got some).

 

I can't test or verify this as:

 

I don't have a Dapol 68, my DCC equipment is at the Lincoln show on my demo stand for the weekend, and I don't have an MX634 to hand.

 

Let us know how you get on, please.

 

Kind regards,

 

Paul

I've had access to a controller again and can confirm the CV8 change works to get bring the Halos to life.

 

Might experiment inline with Nikabd post too later

[Pegleg90]

I've had access to a controller again and can confirm the CV8 change works to get bring the Halos to life.

 

Might experiment inline with Nikabd post too later

 

Hi NaN

 

Take it all the lighting functions worked fine (i.e. as per Dapols instructions) once you did this change to CV8?

 

Thanks

Ali

[NaN]

Hi NaN

 

Take it all the lighting functions worked fine (i.e. as per Dapols instructions) once you did this change to CV8?

 

Thanks

Ali

As far as I could tell, yes. It takes a little getting used to and the can lights are via the circuit board switches.

[johnreed100]

I have fitted a Zimo MX634D DCC decoder to my Class 68 which I am very impressed with.

 

All lights work OK with the exception of the Halo lights. Appreciate any advice on how to get the Halo lights working by changing the CVs. Don't have the skills to re-wire.

 

Have changed CV8 to 3. This results in the rear Halo lights flashing - this is the only progress I have made.

 

Thanks

[NaN]

I have fitted a Zimo MX634D DCC decoder to my Class 68 which I am very impressed with.

 

All lights work OK with the exception of the Halo lights. Appreciate any advice on how to get the Halo lights working by changing the CVs. Don't have the skills to re-wire.

 

Have changed CV8 to 3. This results in the rear Halo lights flashing - this is the only progress I have made.

 

Thanks

Have you adjusted the tiny switch on the motherboard (switch 3)? Edited March 5, 2017 by NaN

[russ p]

On the real thing it's impossible to have the headlights on without the halo's

[markw]

I have fitted a Zimo MX634D DCC decoder to my Class 68 which I am very impressed with.

All lights work OK with the exception of the Halo lights. Appreciate any advice on how to get the Halo lights working by changing the CVs. Don't have the skills to re-wire.

Have changed CV8 to 3. This results in the rear Halo lights flashing - this is the only progress I have made.

Thanks

You need to set CV124 bit 7 to change change from SUSI outputs to function outputs.

If you have not changed any of the other settings for CV124 write 131 to CV124.

[markw]

On the real thing it's impossible to have the headlights on without the halo's

On the real thing the top marker comes on with the halos not with the headlights.

[charliepetty]

You could always put a worry free ESU V4.  Charlie

[russ p]

On the real thing the top marker comes on with the halos not with the headlights.

The top one is on when any of the white lights are on.

The top one is just a marker and doesn't have a halo.

Unfortunately when running across the Broads at night it draws the attention of owls for some reason

[markw]

The top one is on when any of the white lights are on.

But it is not like that the way that Dapol have connected it, it is only on with the headlights.

Edited March 5, 2017 by markw

[russ p]

But it is not like that the way that Dapol have connected it, it is only on with the headlights.

Well I can assure you that is wrong

[LMSfan72]

Hi, I know I'm resurrecting an old thread, but, I thought it worth mentioning a development regarding installing a non-MTC 21-pin decoder.

 

I took delivery of a secondhand Class 68 DRS Astute yesterday - Dapol 4D-022-008 (DCC Ready). I was intrigued by this post because I want to install a ZIMO MX644D as John has done. The interesting thing I found when removing the body is that my version does NOT have the bodge wiring - it appears to be as it left the factory, so nothing removed/modified. So, I thought I'd explore to see what is different.

 

I happened to have a spare Digitrax SDH186MT sound decoder. This decoder is helpful because it too has the ability to switch AUX3 and 4 between logic level and 12V by changing CV64 from 0 (logic, MTC compliant) to 64 (12V output like F0 and AUX1,2).

 

I set the following on the control switches:

 

Directional Cab Lights (switch with F0)

 

SW1 - P1

SW2 - P1

 

6-function DCC

 

SW3 - P1

 

Both End Lighting Control:

 

SW4 - P1

SW5 - P1

 

The below is the lighting behaviour I get with the standard mapping (F0f and F0r on F0, AUX on F1, etc....). End 1 is non-fan end

 

With CV64 = 0 (logic level)

F0 ON + Fwd - End 1 Headlights (top and bottom) on, End 1 cab on

F0 ON + Rev = End 1 rear lights on, End 2 cab on

F1 ON (dirn independent) = End 2 Headlights (top and bottom) on

F2 ON (dirn independent) = End 2 rear lights on

F3 ON (dirn independent) = End 1 marker (halo) on

F4 ON (dirn independent) = End 2 marker (halo) on

 

So, I figured that was what I more or less expected with the normal mapping.

 

Now I changed CV64 = 64 to switch to 12V AUX 3 and 4, and here is what happened:

 

With all functions OFF, the halos at both ends were lit up, but:

 

F0 ON + Fwd - End 1 Headlights (top and bottom) on, End 1 cab on

F0 ON + Rev = End 1 rear lights on, End 2 cab on

F1 ON (dirn independent) = End 2 Headlights (top and bottom) on

F2 ON (dirn independent) = End 2 rear lights on

F3 OFF (dirn independent) = End 1 marker (halo) on

F4 OFF (dirn independent) = End 2 marker (halo) on

F3 On (dirn independent) = End 1 marker (halo) OFF

F4 On (dirn independent) = End 2 marker (halo) OFF

 

 

I.e the effect, on this board, with the Digitrax decoder was simply to invert the behaviour of AUX3 and AUX4 - i.e. all 6-functions still work but the behaviour of F3 and F4 are normally on rather than normally off. Now, I don't know if this is just a peculiarity of the Digitrax 12V output, I doubt it, but I am now waiting delivery of my ZIMO chip to confirm.

 

So, a non-"bodge" board may not require any mods whatsoever!

[LMSfan72]

Well, the postman brought the MX644D this afternoon. So, a quick install later and......... it does NOT behave like the Digitrax! The halo's aren't lit up and won't switch. I guess that the voltage output is just that bit higher so the electronics on the board don't work the same... So, now to figure out whether John's mod will work on the non-bodge wire board!

[charliepetty]

Well, the postman brought the MX644D this afternoon. So, a quick install later and......... it does NOT behave like the Digitrax! The halo's aren't lit up and won't switch. I guess that the voltage output is just that bit higher so the electronics on the board don't work the same... So, now to figure out whether John's mod will work on the non-bodge wire board!

The Legomanbiffo 'ESU' decoder works the Class 68 as its intended, Dapol use that decoder in there factory fitted ones.     Charlie