O Gauge 1st Generation DMU By Paul Chetter / Digitrains

[GBRf66701]

Hello,

 

I hope someone can help with this, I have a O gauge Derby Lightweight and i am fitting a Zimo MX645R with sound by Paul Chetter. I have wired up the DMU and it is all working fine with directional lighting. I wanted to fit interior ligiting in and have it on a separate function but all the functions avaliable appear to be used by sounds. There is a brown and green wire spare but when i linked them to the lighting and turned all the functions on i got nothng. Can any one tell me how to get the lighting onto the green or brown wires?

 

thanks

Matthew

[66C]

Hi Matthew

 

Have you spoken to Paul at Digitrains?

 

He is very approachable and helpful.

 

Regards.

[pauliebanger]

Hi Matthew,

 

I'm Paul and I create sound projects for Digitrains, including the DMU you have, but I am not employed by nor am I in any way part of Digitrains, though Nicole and Jeremy are friends of mine.

 

If you are using LEDs remember that you will need a resistor in series to restrict the current to safe levels. I normally recommend a minimum of 1KOhms, but you might find higher values give a more prototypical intensity, i.e. dim.

 

There is an understandable confusion which arises with the terminology, especially as it is often used 'losely'.

 

Many of the F Keys do have sounds assigned to them, but physical Function Outputs (say for lighting) are a different thing. They require two stages. 1 ) the physical connection to the item to be powered and 2 ) internal software assignment of the FO to the required F key.

 

Physical connections: the green and the brown wires are Function Outputs (FOs) 1 and 2 respectively. The positive supply to all 'normal' FOs is provided by the blue, Common Positive, wire. This must be connected to the positive terminal of each item requiring power (excluding the motor), the negative terminal should be connected to a FO, in this case either the green or the brown.

 

Software assignment: this is refered to as 'mapping' and there are a number of ways to do this with ZIMO decoders ranging from the fairly proscriptive NMRA mapping,not really suited to sound decoders, to one of several ZIMO Extended Mapping options. By far the most flexible and convenient is so called Swiss Mapping. You can find out how to do this from the ZIMO 'small decoder manual' downloadable from the ZIMO website, or from my Swiss Mapping thread in the DCC sound section.

 

If your DCC system can access F Keys above 20, then it will be fairly straightforward as there are unassigned keys from F21 to F26 which can be used for these lights.

 

Assuming you decide to use the green wire, FO1 and F key 21, here's how to assign the FO to the F key.

 

CV430 = 21 (the number of the F key)
CV432 = 1   (the FO number to operate when travelling forward)
CV434 = 1   (the FO number to operate when travelling in reverse)

 

FO 1 (or FO 2) may have special features assigned, depending upon the version of the sound project loaded.

 

Ensure CV127 and CV 128 each have a value of ZERO.

 

So, if you have the blue wire connected to the lighting positive and the green wire (FO 1) to the negative, F key 21 will turn the interior lighting on or off as you wish.

 

If you need to used an F key below F 20, you will first need to remove the sound from that key. This can be achieved via ZIMO Input Mapping or another CV based technique.

 

Get back to me if you need further help on this.

 

Kind regards,

 

Paul

[GBRf66701]

Hello Paul,

 

Thank you for you reply, I have tried the settings you suggested and have got one coach's interior lighting working on the green wire but when i link the second coach all the lights begin to flash. I wanted to try and run the second coach from the brown wire to see if it would cure the problem. There is no short in the second coach, as the work on an LED tester, but the LED's are a different make and i was not sure if this was causing the problem. Please can you send me the settings for the brown wire and do you have any ideas as to what may be causing the problem.

 

Cheers

Matthew

[pauliebanger]

Matthew,

 

I don't know know what is causing the flashing when you link up, sorry.

 

The CVs to assign the brown wire:

 

To switch both units together

 

CV436 = 21
CV438 = 2
CV440 = 2

 

To have the 2nd unit on a different F key, say F22

 

CV436 = 22
CV438 = 2
CV440 = 2

 

The second suggestion might be best to try first so you can try to isolate the reason for the flashing.  

 

Kind regards,

 

Paul