Function mapping Zimo MX644D

[AdeRail]

Hi,

Ok I will explain this the best I can,

i have just finished installing my shiny new MX644D Sound chip from YouChoos into my class 57, I’ve added some cab lights in both ends with the positives going to the blue common positive on the harness wire and negatives going to the Function Outputs on the chip. Soldered one to pinout 5 and one to pinout 6 via the very small solder pads on the chip.

 

 

Now I’m trying to work out how to actually get the lights to work, man it’s complicated, I’ve been reading all night and I am still non the wiser, apart from knowing that I have to link the aux 5 & 6 outputs on the chip to a function Button in railmaster.

 

 

How though..... the instruction manual is giving me a headache...

[Fozzy Bear]

I had a look at the manual and I see what gave you the headache! The amount of info is staggering.

 

Pinout 5 & 6 seems wrong. I think it should be 7 & 8.

8 will be for the front light and 7 will be for the rear. Just a normal F0 button should operate them and they should be directional.. I compared the manual to a standard pin layout picture and it seems to be drawn upside down.

This is the reference I found

http://www.sbs4dcc.com/images/209_21MTC_Pinout.GIF

[Chrissaf]

Fozzy, AdeRail is referring to auxiliary "Cab Lights" not 'Directional Lighting' (the Cab Light mod was covered on another post of his).

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But AdeRail, I do agree with Fozzy that pins 5 & 6 are NOT the correct pins. Pins 5 & 6 on the MTC21 pin connector of the decoder are to do with timing.

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Since you mention two pins, then I take it that you want to control the Cab Lights at each end of the loco independently, rather than both Cab Light ends coming on together. And that the Cab Lights are independent of the 'Directional Lighting'.

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From the MX644D manual. You therefore need to connect one Cab Light (suggest the front one) to the Decoder AUX 1 output, which from the Zimo manual is FO1 (MTC21 connector pin 15) and the other end Cab Light to the Decoder AUX 2 output, which from the Zimo manual is FO2 (MTC21 connector pin 14). See images further below for detail.

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Again according to the manual, the default mapping for FO1 and FO2 is F1 and F2 respectively. This assumes that the sound installer has not remapped these functions because of the 'soundscape' files they have installed. I have modified the manual drawing below to show the FO2 Cab Light.

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OK, I have identified that you need the FO1 (AUX 1) & FO2 (AUX 2) outputs (Pin 15 and Pin 14) but where are they.....see below.

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The diagram Fozzy gave a link for is below with some yellow highlighting added.

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Note that AUX 1 (Pin 15) & AUX 2 (Pin 14) are near the VCC pin 12 [VCC is termed +5V on the Zimo manual drawing] - see below.

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So using the VCC (+5V) pin as a pin location reference pin. You can see that the Zimo drawing is rotated 180 degrees compared to the normally accepted standard drawing (Fozzy's) for a MTC21 decoder connector. It would have been more obvious and helpful  if Zimo had included some pin numbers on their graphic to supplement the pin description text.

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The information in this post, should hopefully be detailed enough to sort you out. If your controller F1 & F2 commands do not operate your Cab Lights it will be necessary to consult Chapter 5 in the manual to try and deduce what function mapping has been implemented by the sound installer.

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EDIT: The Zimo manual is a multi decoder manual, hence why it is such a complicated read to trawl through, thus the drawing above titled MX640D is representative of the MX64nD series of decoders and includes the MX644D.

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[AdeRail]

Hi,

 

Fozzy, that’s the wrong pinout diagram, I wish I could add pictures as I have one but can’t find a link to it on the web.

 

 

[Rog RJ]

Should be pins 15 and 16 I think. 16 is the common positive and 15 is auxilliary 1

 

http://youraccount.ekmpowershop2.com/ekmps/shops/aandhmodels/images/nem-660-21mtc-icons-%5B2%5D-36102-p.jpg

[AdeRail]

My decoder layout on the index pin side is thus,

Sorry Negatives soldered to Function Output 5 & 6 not pinout 5&6

 

index pin (blank)

Loudspeaker

Loudspeaker

Front Headlight (F0f)

Rear Headlight (F0r)

Susi Data (servo 2)

Susi Data (servo 1)

Function Output 4

Function Output 5

Function Output 6

Switch Input

 

 

Negatives soldered to Output

[Chrissaf]

AdeRail, the pins you have highlighted as FO5 & FO6 are shown as "n/a" on the MX64nD series decoder pinouts. In a full MTC21 pin out configuration these pins would be input switch pins 2 & 3 usually used for 'Hall Effect' detectors. Hall Effect detectors are typically used on locos to detect wheel rotation rates to control steam chuff - thus they will be inputs and not outputs. I assume you must be looking at the wrong manual graphic (I do stand to be corrected though.....tell me the Zimo manual page number your drawing is on and I will check again).

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My earlier reply has been heavily edited over time as I added more detail to it. You may not have seen the final edit yet, so do please scroll up and review the changes I have made. I agree with Rog regarding Pins 15 & 16 (16 being the blue +ve return). Plus my additional Pin 14 of course for AUX 2.

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Note: Fozzy's diagram isn't wrong. It shows the NMRA standard for a MTC21 pin connector that ALL decoder manufacturers making 21 pin decoders should be adhering to.

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Given that the Cab Lights are not working on the pins you have connected to, then logically it is more probable that our combined assessment of where you should connect the lights is more likely to be correct.

[AdeRail]

 

While I try to digest all this, the diagram I am going from is the one on the decoder leaflet and it has a picture of the decoder albeit the other way around from standard.

 

Shown on page 9 of the instruction manual.

 

 

With pins listed like this

 

 

                            +5 - - index pin (blank)

   Function Output 3 - - Loudspeaker

   Function Output 2 - - Loudspeaker

   Function Output 1 - - Front Headlight (F0f)

Common/Capacitor - - Rear Headlight (F0r)

     Capacitor Minus - - Susi Data (servo 2)

               Motor Left - - Susi Data (servo 1)

            Motor Right - - Function Output 4

                   Ground - - Function Output 5

                  Rail Left - - Function Output 6

                Rail Right - - Switch Input

 

 

The dashes in the middle represent the pinouts, it’s the best I can do on an iPad.

[Chrissaf]

This is the MX644D diagram on Page 9

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The Zimo use of pins 2 and 3 for FO5 & FO6 is I believe a deviation from the NMRA standard. I can't see in the online manual where FO5 and FO6 might be mapped to.

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You could try operating all your Functions in turn from F1 to F2? and see which ones if any operate the cab lights.

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On one of my factory installed Loksound decoders the Cab Light shares the same F key as a play once spot sound. Your FO5 & FO6 might also be mapped to a sound function too.

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If that doesn't work, then why not try FO1 & FO2 (Pins 14 and 15) as documented in my earlier reply.

[AdeRail]

It was hard enough getting FO5 and 6 soldered to the board, and they were on the edge, I don’t think I would chance sticking my soldering iron into and between FO1 and 2......

 

 

Railmaster might be a problem too because it doesn’t have this chip in its program, would I just assign the “cab light/on off” Function to every f key from 1 to 25 and see if this works?

 

Also how would I re-map the cab lights function once I’ve found it to another F key?

[Chrissaf]

I'm pretty good at reading technical manuals, but the Zimo one is not at all an easy read by any stretch of the imagination. There are some references to mapping in various parts of the manual.

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On page 70 there is this reference:

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This basically says that function mapping is detailed in Section 3.14 of the manual (starts on page 24). On page 24 there is this table:

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Now the key things I see in this table is that references in other parts of the manual that talk about FO, FO1, FO2, FO3, FO4, FO5, FO6 etc are documented as FA(n) and not FO(n) on this table [see the yellow highlight in the very first sentence of text].

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So assuming that the FA5 and FA6 entries are in fact functions FO5 & FO6 (FO meaning Function Output - I can't figure out what the A in FA stands for). Then these are mapped by default [yellow highlighted lines in the table] to F5 and F6 respectively.

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Now it is highly probable that F5 and F6 will also double up as 'spot sounds'.

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Now with regard to remapping FA5 (assuming this is FO5) and FA6 (FO6) to a different F function key. It appears you are limited to only being able to choose a function number between F1 and F12, this being a limitation of a binary 8 bit restriction (as explained in the manual text at the top of the page). Plus if you do remap to another function you are displacing the function already mapped on the F number you want to move it to. It all starts to get very complicated. The remapping is implemented by changing values in CVs 33 to 46.

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To further complicate the manual, the values highlighted in grey in the page 24 table that number horizontally from 0 (right hand side) to 7 (left hand side) represent Binary Bits in an 8 bit word. The slanting text example below this table is using 'Decimal' numbers. This is Zimo's attempt to explain how to use the table, and is an important thing to understand if you were to attempt to perform any function remapping.

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Let me try to explain further:

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Look at the F6 row for CV40.

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In the grey highlighted table this shows the number 4 (which is the fourth Binary Bit) as the default setting, in the slanting text, CV40 is shown as a default decimal value of 16.

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Now in Binary, the fourth bit (Bit 4) is decimal 16 from:

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So if you wanted to remap F6 to FA9 (instead of the default FA6) you would have to write decimal value 128 into CV40 to set Bit 7. As you can see from the grey highlight in the table, the remapping options available are quite limited.

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Further Examples:

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If you wanted to remap F11 & F12 to FA5 (FO5) & FA6 (FO6) respectively, then you would write decimal value 1 to CV45 and decimal value 2 to CV46.

OR

If you wanted to remap F3 & F4 to FA5 (FO5) & FA6 (FO6) respectively, then you would write decimal value 8 to CV37 and decimal value 16 to CV38.

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However, by doing the above you have potentially dislodged the original functions on F11 & F12 and/or F3 & F4 so the impact of that needs to be taken into consideration too. The ones you dislodge need to be remapped to the now vacant F5 and F6 functions.

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In conclusion, first I would try F5 and F6 and see if these operate your Cab Lights. If not, run through all the F numbers as previously suggested. Unless you are a logically minded puzzle solver (i.e the grey table), you may have to leave the Cab Light functions on whatever F number you find them on.

[LMSFan72]

Railmaster might be a problem too because it doesn’t have this chip in its program, would I just assign the “cab light/on off” Function to every f key from 1 to 25 and see if this works?

In railmaster you don't need to set those labels up just to test. The buttons will work regardless. However, for testing I typically set them to "F0 on/off", "F1 on/off"  etc so that I can easily know what I am doing on the loco control big and small windows, confirming that the expected function is working correctly. Making them latch with the on/off is best to see the lights come on otherwise you'd just see a flash or nothing if you werent quick enough!

I have remapped the same decoder and Chris's interpretation matches my own - and mine worked succesfully.

 

 

 

 

 

 

 

[Chrissaf]

AdeRail, LMS is correct. The text description on the Function Button labels in RM are just there to suit us humans, there is no need to relabel them all as 'Cab Lights' just for testing purposes. He is also correct about the need for the "on/off" text to make the function latch on, else as he says, the 'Cab Lights' will only give a brief flash (about 2 seconds).

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A humorous story: There was another post on the forum where a newbie was under the impression that by changing what the label says, changed the 'sound' the function made. He couldn't understand why when he changed the label from 'one whistle' to 'two whistles' using the 'pull down' selection box, why the decoder still played a single toot. The only text on the label that makes any difference is the "on/off" text. RailMaster takes absolutely no notice of what else might be written on the label.

[AdeRail]

Ok this is just not working for me, I have tried it on both railmaster and my Merg setup, and non of the F keys 0 - 25 Switch the cab lights on.

 

 

I changed all the f keys in railmaster to on/off. Nothing.

 

 

Ive emailed YouChoos but as yet had no response, I’m probably not grasping all this correctly either.

 

 

Thanks for all the help though, it will all be so useful when I get that lightbulb moment and it all makes sense!

 

If I forget about re-mapping the keys and just concentrate on simply finding which key turns the cab lights on, how come no keys on both of my controllers activate the lights?

It’s just finding which function key activates FO5 & FO6.

 

Now the other thing I am wondering is, is it anything to do with the 21pin MX644D chip being connected to the 8pin loco via a Hornby sapphire harness?

The negative of the cab lights go directly to the Solder tabs for FO5 & 6 on the chip and the positive is spliced into the common positive blue wire on the harness, should these positives go directly to the chip also? Or doesn’t it make a difference..?

 

 

I really do appreciate the vast amount of information you have given me, I’m just a bit befuddled at the moment.

[LMSFan72]

AdeRail - perhaps you can read CVs 61 and CVs 33 through 46 and let us know the values.

Also, maybe you can provide a photo of your connections to the decoder if you can get one to upload? Andy

[Chrissaf]

I don't see the blue wire as being the issue. I take it your directional lights work OK, they wouldn't if the blue wire wasn't getting a positive voltage on it.

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To progress this further in diagnostic terms you really are going to need a multi-meter if you haven't got one already to measure voltage. With the positive of the multi-meter on the blue wire, use the negative of the meter directly on the decoder pins. Use the controller to send the Function command (start with F5 & F6, but you might have to try the others as well). Use the negative of the multi-meter to see which decoder pins have the negatives on it (write them all down on paper). Now send the same Function command again and see what pin (if any) loses the negative voltage. The pin that loses the negative voltage is going to be one associated with the Function command sent. This is going to be a long laborious process with lots of note taking, but it should identify what pins are switched negative by what functions.

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The above assumes two things, that the decoder is not damaged in any way (i.e has your wire soldering shorted something, as you said yourself the solder pads are small and difficult to get at). Secondly it assumes that your custom Cab Light wiring has some kind of fault in it. If it didn't have a fault then one would expect that a fully working decoder would light up the Cab Lights on at least one of the 25 Function keys you have tried. Are you absolutely sure that the Cab Light wire connected to the decoder 'blue' is the one that goes to the LED anode. Have you perhaps just simply got the LEDs the wrong way round as they only light up when the correct voltage polarity is applied. Do they still light up with a battery connected to the LED wires, have you inadvertently done something that has blown them, since you last tested them.

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If during this testing process you find that Pins 14 and 15 are switched negative by F1 & F2 commands, then could you not solder your Cab Light wires to Pin 14 & 15 on the Sapphire harness connector rather than directly onto the difficult to access decoder pin tracks. I'm not familiar with how the Sapphire Harness is constructed to assess the feasibility of this suggestion.

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This MTC21 Adapter board made by ESU (for their MTC21 pin Loksound decoders) could alternatively be used in the absence of a Sapphire harness to connect MTC21 pin decoders to alternative wiring schemes. It has the advantage that all 21 pins are easily assessable to attach wires. The eight pins associated with Hornby 8 pin connector can be wired to an 8 pin connector to basically replicate the Sapphire Harness for motor and directional lighting control. The adapter also gives a wiring point for the speaker used with a sound decoder. It has many beneficial advantages over the Sapphire harness. Such as the ability to easily access all 21 pins. Negates the need to solder wires directly to the decoder, making decoder replacement easier. The ability to create custom harnesses that need to access more than just the basic 8 decoder wires.

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The ESU part number is 51967

http://www.digitrains.co.uk/ecommerce/dcc-accessories/51967-loksound-v3.5-21-pin-adaptor.aspx

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The 8 pin connector for the Hornby end is proving a little harder to source. It is a NEM652 Male Plug, but trying to find a supplier is proving difficult. You could perhaps use your Sapphire harness as a donor for this part.

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EDIT: Finally tracked down a NEM652 Male Plug. This one is actually made by ZIMO and has the ZIMO part number "RSTECK" this one sold by "YouChoos". The only supplier I could find based in the UK.

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http://www.youchoos.co.uk/Index-Shop.php?L1=Electronics

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Also found this component from RailwayScenics. RS claim it can be used either as a plug OR a socket. Solder the wires in the holes and it becomes a plug, or so RS claim. It would make a plug much more easy to terminate wires on if it works.

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https://www.railwayscenics.com/low-profile-pin-nem-652-dcc-decoder-plug-or-socket-p-1927.html    

[LMSFan72]

I thought I'd take a picture of mine. The 3 additional wires soldered to the board socket pins are: copper AUX4/pin4, blue AUX3/pin 11, black AUX2/pin12. I am expecting that AdeRail has his wires on the 2 pins "above" my copper wire. I confess to never having tested that the MX644D has the full 8 functions (i.e AUX5 and AUX6) plus the 2 logic level outs but I am pretty sure it does. I did note that the manual page 3 says 6 functions even though the diagram does show FO5 and 6.

 

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[Fishmanoz]

It’s morning here but the coffee is starting to kick in to the extent the content here is making at least superficial sense. So let me try to make a very brief summary of this lot for AdeRail. 

 

I think from the very very start you set the hares off in a slightly wrong direction by using the terminology function mapping when what I think you meant was just function assignment (What pins do I need to connect my cab lights to that are currently unused auxiliary outputs, and what are the function numbers for those outputs?).

 

If that is your question then Chris has told you the answer against his diagram of the decoder pin assignments (pins 15 and 14), and he’s told you the function numbers for those (F1 and F2).  He’s then even told you how to test to see if this is correct by multimeter connection to those pins while operating the latched (on/off) functions in RM.

 

Finally on your soldering difficulty, he’s given you a board which gives you easy solder pad access to all pins.

[Chrissaf]

I've just noticed something on the ESU MTC21 51967 Adaptor board that needs highlighting. It relates to the solder pad numbering. The pads numbered 11 to 21 should really be numbered 12 to 22 to fit in with the MTC21 pin allocations. Pin 11 doesn't exist, so it shouldn't have a solder pad labelled as Pin 11.

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See graphic below for explanation:

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[AdeRail]

Yes Fishy, perhaps “Function assignment“ would have been a better term,

 

But however my cab lights are connected to pins 2 and 3, FO6 & FO5, and what I really need is to find out what the function numbers are for those, and seeing as non of the functions work I’m stuck.

 

 

Maybe I don’t know enough about this yet, as most of it is flying over my head, or maybe I have a case of too much information...

 

Anyway I received a reply back from youchoos so hopefully they can help with their next reply, maybe it has something to do with CV61 being 97

 

For Andy above the cvs you wanted are:

 

33 = 1

34 = 2

35 = 0

36 = 0

37 = 0

38 = 0

39 = 0

40 = 4

41 = 0

42 = 0

43 = 0

44 = 0

45 = 0

46 = 8

[Fishmanoz]

That’s the problem, wrong pins, you need 15 and 14.

[96RAF]

I already said somewhere that the Sapphire adapter doesn't have all the 21 pins connected so no wonder many of the assigned function outputs don't work.

 

Once you have wired up the full set on the ESU/GM/DCC Concepts/other adaptor they should at leas twork on the default settings (after a reset of course). Note also what has been said about certain outputs being logic rather than full fat voltage.

 

Dont you just love translated manuals. You could start a new topic listing outtakes from them.

 

Rob

[LMSFan72]

Ok. Looks to me like it’s your CV settings. With CV61 set to 97 you are on the second table in Chris’s post. The only functions outputs that are mapped to turn on are the non-zero values.

For example CV40 = 4 is bit 3 so that is FO1 and CV33 and 34 are doing your directional lights on F0.

 

I would try CV61 = 0 and then set CV39 = 8 and CV40 = 16. That puts you in the left hand table and should put FO5 and 6 on F5 and F6.i have also uploaded a photo of my connections but that will be waiting moderator approval. Andy

[LMSFan72]

AdeRail: I just checked what the default values were on my chip and they are the same as you currently have. Youchoos have mapped it so that F6 is AUX3/FA1/FO1 and F12 is AUX4/FA2/FO2.

 

(I'm not sure what you have assigned to those outputs if anything so you might want to use those so that you don't affect the sound function on F5. Up to you. You could also map it so that the one key turns on both cab lights, or the one key turns on the cab light in the direction of travel, or as I have, which is 1 key turns on cab light in direction of travel when stationary only (this is more complicated but it is CV only)).

However, in the light of how Youchoos mapped it you may want to leave CV61 alone (=97).

 

In that case for F5 and F6 to switch FO5 and FO6 you would need:

CV61=97

CV39=64

CV40=128

 

This will leave F12 doing FA2 as Youchoos set it. I'm pretty sure that will do it for you.

 

Andy

[Chrissaf]

AdeRail,

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I have drawn up four tables below. Which tables you use as reference will depend upon the value of CV61. If your CV61 reads 0, then use Tables 1 & 2. If your CV61 value reads 97, then use Tables 3 & 4.

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Based upon the values you posted earlier for CV33 to CV46, they show that functions for FO5 & FO6 have not been assigned to any Function F keys. This is obviously why your Cab Lights are not working. My tables below ignore CV33 & CV34 as these are your 'Directional Lights' and should not be touched.

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Table 1 shows the Function Key allocations based upon the CV values you read and reported earlier. Based upon a CV61 value of 0.

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You can see in Table 1 that your CV40 value of 4 assigns F6 to FO4 and that the CV46 value of 8 assigns F12 to FO8. You can also see that FO5 & FO6 your decoder pins 2 & 3 have no current F Key assignments.

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Table 2 shows what decimal values you need to write to which CV to assign the FO5 & FO6 functions, based upon CV61 being zero.

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So looking at the table above, if you wanted to assign FO5 to F5 you would write 8 to CV39 and if you wanted to assign FO6 to F6 you would write value 16 to CV40. This is just an example. You can use the table above to assign FO5 & FO6 to any of the 12 functions from F1 to F12. Remember that CV61 needs to be Zero for this table to be applicable.

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PS - I would avoid using F1 for your Cab Lights. F1 is usually the main 'Sound On/Off' function key on Sound Decoders.

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Now if your CV61 value is 97 as your earlier post inferred, then Tables 3 & 4 are the ones to work from. I would double check your value of CV61 to confirm its current value because your earlier post quoted a value of 8 for CV46, but CV46 is not applicable to Table 3 if CV61 reads 97. It may be that CV46 is still applicable to F12 (in Table 1) even if CV61 is not 0. The manual is not very clear on this point.

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Table 3 shows the current assignments based upon the CV values you previously quoted if CV61 is 97

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Table 3 shows that only F6 is assigned, in this case to FO1.

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Table 4 shows what decimal values you need to write to which CV to assign the FO5 & FO6 functions.

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So looking at the table above, if you wanted to assign FO5 to F5 you would write 64 to CV39 and if you wanted to assign FO6 to F6 you would write value 128 to CV40. This is just an example. You can use the table above to assign FO5 & FO6 to any of the 8 functions from F1 to F8. Remember that CV61 needs to be 97 for this table to be applicable.

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PS - I would avoid using F1 for your Cab Lights. F1 is usually the main 'Sound On/Off' function key on Sound Decoders.

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The above concurs with the posts made by LMS above in posts timed at 07:13 & 08:55.

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Your next task is to confirm the value of CV61 to decide which two tables you want to use.

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Note: The tables above have been generated from data contained on Page 24 of the Zimo Decoder Manual.