DCC 4TC using Zimo MX686

[50033]

Afternoon all. 
Making the most of Kernow selling off some damaged box 4TC units, I’ve finally got my self a unit. I’m DCC so purchased a Zimo MX686 to fit. Having fitted the chip, I can’t get my interior lights working. So I read all the posts I can find on here and tried turning the susi off to normal operation by setting cv124 bit 7 to 1. Still nothing. 
Am I right in thinking I should be using F9 to operate the interior lights, because I’ve turned all 28 functions on my lens handset to on and still no joy. 
F0 turns head ode lights on and off and F1 and F2 turn individual ends off so it’s definitely working. I just can’t work out what else I can do. 

[Nigelcliffe]

Assuming the following, if not, then ignore the posting:  this is a MTC-21 pin decoder, and your interior lights are on function outputs 3 or 4.   Then the issue may be "there are two 21 pin standards, and they're different". 

 

Try the two different resets for the Zimo decoder, to switch between the different 21-pin standards.   Chances are a reset may also reset other things, such as address or other features,  its so long since I did this change for a 21pin Zimo that I can't remember what else changes.  

CV8=3   converts decoder to a "C" version, with "logic level" outputs on Fo3 and Fo4

CV8=4   converts decoder to a "D" version, with "full power" outputs on Fo3 and Fo4. 

 

Its in the Zimo decoder manual for function decoders, and at least Zimo lets you swap a decoder to work with both of the standards. 

 

 

[50033]

Thanks for that. I did see about cv8 on another thread for locos so as I couldn’t find it in the function only instructions haven’t tried it yet. If nothing else is suggested that will be next to try. Thanks

[RFS]

6 minutes ago, 50033 said:

Thanks for that. I did see about cv8 on another thread for locos so as I couldn’t find it in the function only instructions haven’t tried it yet. If nothing else is suggested that will be next to try. Thanks

 

On my unit I have a Lenz 21-pin chip and it's F5 that turns the interior lights on and off. 

[50033]

Yeah thanks RFS but I’ve turned every single F on and off and nothing works for interior. I’m sure it’s something to do with the susi logic of the Zimo chip. 

[Nigelcliffe]

55 minutes ago, 50033 said:

Thanks for that. I did see about cv8 on another thread for locos so as I couldn’t find it in the function only instructions haven’t tried it yet. If nothing else is suggested that will be next to try. Thanks

 

Stuff on other forums says the interior lights of the units are logic level.  The default version of Zimo decoders in many UK retailers are "D" (full power).    So I think my suggestion may work.  There is not much to loose by trying it.   

 

The Suzi connections are on outputs Fo5 and Fo6 :  which are the 7th and 8th function outputs (front and rear lights being 1 and 2, then Fo1, Fo2, etc..).  

 

The reset stuff is in the English Language version of the Zimo manual, under the diagram showing the pin-out of the decoder.  

 

- Nigel

 

[50033]

Nigel your a genius. Cv8 to 3 equals lights in F3. Thank you so much.