Does anyone know about the new M84 - 60842? There is a B/O terminal which is to connect to the track (I am using C-tracks) to pick up the digital signal and the track power which is to switch the 4 groups of relay on the M84. If I want to use the M84 to turn o and turn off my street/building lights, and also use it to control the Viessmann light signal 4013, do I need an additional power supply (either a transformer or a switch mode power pack)? My understanding is the power from the B/O terminal is used to switch the 4 groups of relay to RED or GREEN position but not to power the 4 relay output (the devices connected to the 4 relay output). Can anyone provide me a wiring diagram how to connect the street lights and the light signal to the M84? Furthermore, how does the CS2 recognize the M84? Do I need to register the M84 to the CS2 before using it?

Thanks for your information. I got that manual too, but how do I register the M84 to the CS2 and how to connect the Viessmann 4013 to the output terminal? Do you also know whether the B/O terminal would supply power to the 4 output terminals?

Personally I would not attempt the autoregistration (mFX)

For manual registration,

- from the CS2 Keyboard , locate a free range of (4) addresses and edit the item in the keyboard screen

- specify "New multidecoder"
- optionally set the DCC mode if desired

- Observe the DIP switch icon at the top right
- set the m84 DIP switches as per this image

- Optionally
- - edit the icon to a more appropriate one
- - give the item a name

Maerklin issued in its MM 04/2014 an article about the m 84. Find the article here:

https://www.maerklin.de/...5_Digital_MM_2014_04.pdf

Be aware that the m 84 (60841- grey) is the older decoder, the 60842 (m 84 - black) is the newer one. The 60842 is now understanding the mfx format too.

Here at marklin-users.net I found older threads about the decoders

https://www.marklin-user...477-K84-and-M84-decoders
(if link is not functioning threads name is "K84 and M84 decoders" here at marklin-users.net. You might get via the search function to the thread) and

https://www.marklin-user...ound-for-4-Port-toggling

(threads name: "m83=60831/60832 m84=60841/60842 ( 60821 60822 ) - Dec17= mfx sync of addresses (CS3 <> m8*.2) - Marklin Märklin : Perspective details about new accessory items" - yes very long name - Clapcott started it Oct 27th, 2013)

Our friend Clapcott (here at MUN) made in this thread very detailed description about the decoders m 83 and m 84. In the post #134 also he published a graphic with the power connection.


Finally some pictures in a dutch wiki about programming the decoder m 84 by a CS 2:

https://wiki.3rail.nl/in..._M83/M84-decoder_met_CS2

Note that this predates an update to the CS2 that now offers the more appropriate ability to program CVs in the Accessory(Keyboard) edit screens.

When the m8* was originally made available the CVs needed to be managed (on the CS2) using a proxy locomotive. This is no longer the case.

Select the "Spanner" icon at the bottom left, then either
- if wishing to use the mFX configuration, first register with the "mFX" button
- tap the address of one of the ports on the m84



What are you wanting to program ?

- if its just the icons, then this is a controller function and does not need any m84 programming,

- the DCC v MM operational mode is programmed only via DIP swich #10 - NOT CV programable.

- if you are wanting to program the address, I would highly recommend that you just use the DIP switches (to avoid confusion in debugging in the future). But if this is not satisfactory then an address may be programmed
- - on the programming track only (not POM) for MM and DCC modes
- - on either main or programming with mfX (If the m84 (60842) has been registered as a mfx configurable device)

- In all other CV programming, you may WRITE a CV to the non programming output - with MM you may not be able to address the higher number CVs on some controllers.

- Should you wish to read CVs then this can be done
- - on the programming track (not POM) DCC mode
- - on either main or programming with mfX (If the m84 (60842) has been registered as a mfx configurable device)

On the screen where you see the basic 6 CVs, locate the "open file/folder" at the bottom right
and choose the m84 configuration template. (this will include a line entry for CV38

Note: you can also manually add a template line and specify CV38.


In MM mode , you can only write, not read the CV.

will show a general walk through of the , similar, m83. al be it for DCC

What I am suggesting is that in DCC you can read the CV values when connected to programming track, whereas MM only offers write
Note: even with DCC, POM on the main track is write only.

You can certainly write CV38 when in MM mode, and the indicator lights will flicker in between the usual slow blinking, to indicate that writing is occurring. However it is sometimes "nicer" to be able to read values as a confidence check, and in some cases to know what the existing value is before tweaking them.

Also, MM programming works by cycling power off and on in a certain sequence to set the device into programming mode.
For this you should NOT have external power to the m84 attached, as this defeats this resetting happening.

That said, from experience CV38 is set to 0 from the factory and there is no real danger with setting any value (0 to 10) like there might be with certain motor characteristics.

Cheers
Peter