Fitting decoders and railmaster

[hedley_reynolds]

Hi I wonder if you could please help me with a question regarding the fitting a used decoder to a loco and not knowing which pin is number 1 and if I inadvertently put the decoder in upside down and placing the loco on the programming track using rm and an elink controller would I blow the chip or would I get a message to say that I can't program the decoder with a number and be able to turn over the decoder and replacing it so that I can program and use my loco on my layout as I wouldn't like to cause any damage to the decoder or my loco

i would be very grateful and appreciate again for any help that anyone could give me 

hedley

[Chrissaf]

Assuming your 6 pin N gauge decoder is a NEM651, then it should be wired like this:

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The wire on the socket associated with pin 1 should go to one side of the motor. This should be easy enough to trace. Albeit with a magnifying glass, being N gauge.

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Image courtesy of Brian Lambert's web site.

[hedley_reynolds]

Hi Chris thanks very much for your quick reply and help but my decoder just plugs into the socket and usually it has a white dot on it to show that the pin is number one however I can't see the dot that's usually on the decoder and I wasn't sure if I put it in upside down by accident would railmaster say that there's a short but not blow the chip and then I could correct it and program it as usual 

thanks very much again hedley

[Chrissaf]

Referring back to the image I provided, and assuming that it is correct for your decoder / loco wiring. You can see that your programming controller connections will be the two pins in the middle (shown as red & black). Thus, even if the decoder is reversed, the controller will still be able to see the decoder on the correct two pins (these two middle pins are not polarity sensitive). Therefore there will be no 'short'.

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If the decoder is reversed you will lose motor and lights control and/or strange things might happen, but it is unlikely to cause any damage. One would expect some form of keying in the plug socket arrangement if permanent damage was a feasible possibility. For example the MTC21 DCC 21 pin decoder configuration is keyed (pin 11 is blanked) to ensure the decoder can only go the correct way round.

[hedley_reynolds]

Hi Chris thanks very much again for your help and quick reply and it's greatly appreciated and I'm greatful that you have explained it to me and that if I did by accident put it in upside down that it wouldn't cause damage to the chip and also that it is possible that the decoder could only go in one way round 

thanks very much again hedley

[96RAF]

If you Google 6 pin decoder and click on the images tab you may be able to ID your decoder in the pictures, visit the associated page and glean more information about which is pin 1, or you can read CVs 7 and 8 to find the manufacturer and decoders codes then look them up in the NMRA list.

 

Armed with the type of decoder you can visit the manufacturers web site and see if more info is available.

Rob

[hedley_reynolds]

Hi Rob thanks very much for your help and advice and how to find out which is pin 1 I had never thought about googling the decoder for the info or even for to read the CVs to find out the manufacturer as I thought that you would have to put it in the right way around for programming or reading it but thanks again I'll give it a go tomorrow Hedley