# Add a function decoder to QSI Magnum



## alfischer (Mar 8, 2010)

On The QSI website, they show hooking up a Gwire rcvr to a generic decoder. It appears that motor control would be unavailable. How about hooking up a Function-only decoder in addition to the Magnum for additional lighting controls? It looks like it would basically in parallel with the receiver outlets and there are solder pads on the board. Has anyone tried this or even considered it?


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## Greg Elmassian (Jan 3, 2008)

Considered, but I believe untried as of yet. You need a decoder that will take the 5 volt output of the Gwire, and won't load the output down too much considering that you have 2 decoders in parallel connected. 

You might have some problems trying to run in "service mode" unless you get real familiar with decoder lock. I haven't looked up if the QSI has decoder lock. 

Regards, Greg


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## alfischer (Mar 8, 2010)

You mentioned in another post that the Aux light output of the Magnum was DCC I believe. I'll scope it this weekedn. Looks like it wouldn't be bipolar but I think the decoder wouldn't care. Also a CMOS line driver wouldn't load down the Gwire at all.A short twisted pair would probably do. I would like the aux light functions and looks like a cheepo function decoder could be remapped as desired, like change the mute function to control volume like the mag switch does! Maybe a cab light and a flickering firebox, or ditch lights or... 

(Before I try this I _do_ intend to get one engine running DCC properly!!) Good idea, right?

Ran into an idocincrisy. Power up the engine with the transmitterpower off and you can't do anything. Changed CV29 to 2. Fixed. No analog mode. But battery only is what I want.Don't plan to use analog at all. Playing with the system on the bench and starting to get comfortable with CV's. Of course, the reset has been VERY handy!


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## Greg Elmassian (Jan 3, 2008)

Uhh... I don't think I said the aux light output was DCC... not me.. and if I did, shame on me. QSI says not to touch that output. 

I'd look up the output specs of the LINK receiver chip, you can see the model number on various pictures on the web. 

Cannot program the QSI from the rails if the Gwire receiver is plugged in, if that is what you asked/stated. 

Regards, Greg


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## alfischer (Mar 8, 2010)

I looked up the specs on the Linx chip. Pretty low source. (.24 ma) ut this should drive a CMOS chip. Also looks like the QSI board allready has a chip on it. After I gt my Dutchess running with a standart QSI config I will persue.

OK I won;t touch the Aux out put. Just scope it! I THINK it was you that said the output was DCC. If I can find the post I'll send you the link. I got the Linx chip from Mouser yesterday. Anxious to play with it, But the Dutchess first!


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## N1CW (Jan 3, 2008)

[/b] 
I did add a TCS FL-2 to my RS-3/G-wire QSI decoder.[/b]

The BLACK/RED wire inputs did not 'load down' the 
G-wire Unipolar 5v differential output [/b]to the QSI decoder board.[/b]

I did not 'use' the +5 because there is no current draw rating listed.[/b]

I was able to 'play' with the FL-2 CV's light functions just to see some 
of the different modes.[/b]

Once done, I returned to just FULL ON/OFF (Cab interior and 
Marker Board lamps) CV values.

I did NOT change the DCC address of the QSI nor FL-2.
I could not 'find' a common point to connect the FL-2
so that both Track DCC and G-wire DCC could 'see' the FL-2.
Nor did I see any 'lock' support info for the QSI decoder.
It may require a DPDT switch on the input side of the FL-2.

re: AUX-Lights
The LTG is NOT a dcc signal. It does have a pulse train signal.
Depending on the function key
depressed, the signal could be at ground or +5 between
track DCC vs G-wire DCC. 
.....CAUTION: P3 pin 2 is the LTG signal.

[/b]


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