Hello,

I've bought two Viessmann signals of the KS type, 4043 and 4046, which use the new multiplex technic. I've figured out (I think) how the masts work; would be happy if anybody could tell more. For example, how other types are layed out. Be careful though to apply voltage without resistors to the mast - that would destroy the LEDs I think.

I'm particularly interested to get information about the "signal bus" as well, but have to oscilloscope to measure.


The mast seems to have theoretically up to 12 LEDs, connected between each of the possible connections,
in both directions, with no resistors in the mast. If a current is applied between two connections
with a LED in correct direction, all current flow through this; passing an alternative way = two LEDs in series is impossible
as the forward voltage would add up to a too high level.

I would guess that the idea is to supply + to 1 for 1/4 of the time, and then - to the ones of 2,3,4 that should be lit.
Then for the next 1/4 of the time, + is supplied to 2, and - to 1,3,4 if corresponding LED should be lit, etc.


Plug has four sockets numbered by me as below, and with a marking tag at 1-2 side:

--
12
34

Which gives the table for KS-signals

+ -
1 2 White LED indicating short distance to next
1 3 -
1 4 Red
2 3 -
2 4 Upper white shunt signal
3 4 Yellow distant speed indicator (next signal shows this speed)
4 3 White speed indicator (if reduced)
4 2 Lower white shunt signal
3 2 -
4 1 Green
3 1 -
2 1 Yellow

/Lars

I did just a very simple try with DC+ a resistor; I don't know the voltage. But does it matter? If you do your own module, I think it's good enough to think that there is one LED between each pair of connectors, which I expect of have the ordinary 0.5 V and some ten mA characteristica.
It's not strange that the shunting signals have different connections; if they were in parallell, you would expect one of them to take almost all the current; remember, I don't think there is a resistor in the signal head.

I'm not sure, but think that the "repeater marker" is the same I call "short distance" indicator. White, upper left corner.

I don't know exactly how the current flow is detected inside, but when the signal is initiated the module passes current throw all combinations, seens as "lamp test". It's worth noted that if there is a led "missing" between two points, there are normally alternative ways for the current to flow, passing 2 or 3 LEDs in series. Higher voltage drop - less current though.

/Lars

A LED typically has a voltage drop in the forward direction of about 0.5 V. With less voltage, practically no current flows at all. If you take two LEDs in series it takes 1 V to get current flowing. Hence, if the current has alternative ways, and one of them has only one LED in series, there will be 0.5 V over the net of LEDs, so no current will flow in the other ways.

I haven't opened it. Most because of lack of time.

/Lars

I've had similar problems, and sent my for repair. Drop Viessmann a mail first I suggest.
I've tested my two 5229 on both Intellibox and Daisy system, and one of them is extremely unreliable; just can't see any pattern in what is working or not. The other is much better, especially after reset, but it seems to be worse over time.

Hopefully Viessmann will be able to reprogram them; I find the functionality of 5229 very much to my liking (when/if they work)
/Lars

Just a stupid theory/feeling of mine: it could be that the processor can't process all information it gets in Mixed Motorola/DCC; "not reliable" points into that direction. Sometimes it works, sometimes not. Sometimes press switch several times, and it works for example seventh time. I have tested with both Motorola and DCC on my layout too, but I can't repeat a clear case where it malfunctions every time.

Hope Viessmann solves it, again, the functionality is just what I want (well, I would not mind a LocoNet connection...)
/Lars