Just how does the SUSI bus work?

[phils2um]

OK, it's time I found out how SUSI connections between loco decoders and decoder equipped smoke units, pantograph control boards, etc. actually function. This enquiry was first prompted by the Massoth pulsed smoke unit installed in the mfx decoder equipped LGB LD1 discussion in the Help forum earlier. I have since purchased a Massoth pantograph control board and am curious just how to install it. The instructions are not clear with regard to programming.

The primary question is whether SUSI commands from the loco decoder are automatically acted on by the device's decoder? Does the SUSI bus override the necessity of device decoder address specific commands? Does the device's DCC decoder address need to be set the same as loco's decoder DCC address for it to function? How does a DCC device, such as a Massoth pulsed smoke unit, interface with mfx loco decoders where a unique address is automatically assigned when the loco registers itself?

Any help understanding these questions will be appreciated.

 

[Eeyore.Boater]

OK, it's time I found out how SUSI connections between loco decoders and decoder equipped smoke units, pantograph control boards, etc. actually function. This enquiry was first prompted by the Massoth pulsed smoke unit installed in the mfx decoder equipped LGB LD1 discussion in the Help forum earlier. I have since purchased a Massoth pantograph control board and am curious just how to install it. The instructions are not clear with regard to programming.

The primary question is whether SUSI commands from the loco decoder are automatically acted on by the device's decoder? Does the SUSI bus override the necessity of device decoder address specific commands? Does the device's DCC decoder address need to be set the same as loco's decoder DCC address for it to function? How does a DCC device, such as a Massoth pulsed smoke unit, interface with mfx loco decoders where a unique address is automatically assigned when the loco registers itself?

Any help understanding these questions will be appreciated.

Does this help SUSI - The DCCWiki

 

[phils2um]

I have read the wiki article (and many other bits of info off the web) but it doesn't answer the practical questions I posed. Maybe the answer can only be had by experimenting and praying that the magic smoke stays inside! Could be an expensive learning curve!

 

[Greg Elmassian]

Would be nice to have a "sniffer" for the bus. Had a similar quest on my home automation (Z-Wave) and finally got a sniffer and quickly isolated the problem.

Greg

 

[PhilP]

SUSI does seem a little opaque..

It appears the SUSI commands passed bypass the 'DCC address filtering' of commands, and are more of a 'DO THIS' to the decoder being controlled via this bus?

Something i would like to get my head-around, but no time, at the present..

 

[Greg Elmassian]

Yes I doubt any addressing is going on, since it's really being used for one "node" in a network, normally there are only 2 nodes, maybe 3, but it is really not being used as a bus, i.e. the motor decoder, the sound decoder and a smoke unit all on the same bus, for example.

Greg