Zimo MX680 - function-only decoder

[uk_pm]

I have just acquired 2 MX680 function-only decoders - which are probably overkill given that I only want them to power a tail lamp in a freight train.  However, I can't get them to work.  I have wired up a red LED which briefly flickers when I connect the track power, but I am completely unable to program the decoder (using my ESU 50200), or read its settings.  The manual does not assist, so I am wondering if someone on here may be able to.  

 

All assistance gratefully received.

 

PM

[Nigelcliffe]

Manual is here

http://www.zimo.at/web2010/documents/MX680E.pdf

 

On page three, in the technical note, it explains that you won't be able to read it unless you put enough of a load on an output to generate an acknowledgement pulse.   Typically that means something like 50 to 100ohm resistor, or a small motor.   The attached item can be temporary whilst you read enough CV's to work out what you're doing.  A LED will be far too low a load to pass enough current to cause the acknowledgement pulse to be seen.

 

Some systems refuse to program on the programming track if they fail to get reads from decoders.  Others makers allow "blind writes" where you just write values without doing a read to check its gone correctly.

 

 

- Nigel

 

[uk_pm]

Many thanks for your helpful response, Nigel.  I feel very thick asking this, but where do I connect the small motor (or resistor) on a decoder that has no motor outputs?

[norman]

Just connect between the positive(blue) and one of the functions.

[uk_pm]

Thank you!

[markw]

There is no need to add a load for ZIMO decoders, if cv112 bit 1 is set they will read back ok, this is the default setting for function only decoders.

[uk_pm]

Thank you.  As it happens I’ve had no success whatever (including when I attached a small motor to the white and blue wires), so I have used a loco decoder instead.