General Forum

Re: MasterLink ML specification, protocol, etc.

deaddruid — Fri, 27 Nov 2009 06:43:14 GMT

Herwin,

I've tried to take a copy of your kpc2 repository, but can't easily access the files. The web cvs interface shows the files, but the Summary Page does not have the usual Big Green Button, and the Files page shows nothing.

I've tried using the suggested CVS command:

$ cvs -d:pserver:anonymous@kpc2.cvs.sourceforge.net:/cvsroot/kpc2 login

Logging in to :pserver:anonymous@kpc2.cvs.sourceforge.net:2401/cvsroot/kpc2
CVS password:
cvs [login aborted]: connect to kpc2.cvs.sourceforge.net(216.34.181.110):2401 failed: Connection refused
$

For password, I just pressed carriage return. This all suggests that the repository has moved, or that I'm doing the wrong thing.

Help!

Mark

Re: MasterLink ML specification, protocol, etc.

BeoAffinity — Tue, 03 Nov 2009 14:32:10 GMT

Great! Many thanks to beojeff for the BeoLink Passive hint. After enabling ML via
/MENU/ /0/ /5/ /GO/
/STEP UP/
/GO/
It does work. The light commands do get trough. So this is an easy way to analyse these commands with a home automation system for controlling light, rolling shutter, etc.

Andy

Re: MasterLink ML specification, protocol, etc.

BeoAffinity — Fri, 30 Oct 2009 03:18:59 GMT

Finally, after three weeks I got the BeoLink Passive back with software 1.6. Unfortunately, I had no time to check the behaviour outright. I hope to have some time this weekend to check whether light commands from the Beo4 will pass the BeoLink passive now.

Andy

Re: MasterLink ML specification, protocol, etc.

tournedos — Sun, 20 Sep 2009 03:32:46 GMT

dgillier:

Thanks to the schematics and from an electrical point of view, ML looks very much as RS-485.

Bidirectional asynchronous data transmission on a single balanced wire.

But I don't know if the level are compatible ?

Seeing that the masterlink connector has as a first thing that network of LL4488 diodes as an overvoltage protection, the actual data levels cannot be much more than +/- 500 mV. All common-mode voltages greater of about 1.2V will be shunted to ground and differential levels are limited there as well. I guess the levels need to be kept low to minimize crosstalk into the audio lines, so it might even be much less than this.

This is far from the several volt levels an RS-485 transmitter usually operates, but a (non-terminated) RS-485/422 receiver might be able to read it.

Re: MasterLink ML specification, protocol, etc.

dgillier — Sun, 20 Sep 2009 03:12:05 GMT

Thanks to the schematics and from an electrical point of view, ML looks very much as RS-485.

Bidirectional asynchronous data transmission on a single balanced wire.

But I don't know if the level are compatible ?

If so it will be interesting to connect ML to a PC with a RS-485 to RS232 translator.

Re: MasterLink ML specification, protocol, etc.

BeoAffinity — Fri, 18 Sep 2009 01:39:24 GMT

Thank you for the compliment Evan. I like this picture too and therefore used it for a mouse pad at home as well.

Re: MasterLink ML specification, protocol, etc.

Evan — Fri, 18 Sep 2009 01:33:30 GMT

A little off topic Andy, I must compliment on your avatar, as the very same image is my desktop background! I was waiting for it to show up on an avatar here sooner or later, good pic.

Re: MasterLink ML specification, protocol, etc.

BeoAffinity — Fri, 18 Sep 2009 01:25:09 GMT

Here is a new screenshot of the ML-Analyzer. The BS3000 transmits date and time information via ML to synchronize other devices like link speakers (e.g. LCS9000/BL3500). I wonder if the Audio master would use this information as well. So it would be possible to synchronize all ML devices with a DCF77 clock. In the current setup it is only possible to read ML messages. So I can’t test this – I need more hardware ;-).
Furthermore the Audi master sends source status telegrams if the status changes for example due to a Beo command which changes the CD track or the radio channel.

Andy

Re: MasterLink ML specification, protocol, etc.

herwin — Thu, 17 Sep 2009 13:11:53 GMT

PhilLondon:

Is your software emulating Beoport in Option 0,2,4 or 6?

I thought it was Option 6, but dunno for shure anymore...

PhilLondon:

How did you reverse engineer the protocol? Is there a software on the PC that would allow me to spy on the communication between the Beoplayer software and the Beolink PC 2 box over USB.

Yust use a USB sniffer on windows, you can google on it. It was pretty straidforward.

Herwin Jan

Re: MasterLink ML specification, protocol, etc.

BeoAffinity — Thu, 17 Sep 2009 07:56:54 GMT

Hi dgillier,

Here are the steps:
1.    Open a BeoLink Converter or another B&O device with MasterLink
2.    Find the MasterLink level shifter - in case of the Converter 1611 it is a IC called ML-Asic)
3.    Connect the Rx line to a RS232 level shifter (e.g. MAX232)

The current setup lies on my desk and needs too much space for work. Therefore, in case I got enough information about the ML protocol, I want to prepare a small PCB with the ML- and RS232 level shifter on it, or a PCB with the ML level shifter and an USB Device (e.g. from FTDI).

Andy

Re: MasterLink ML specification, protocol, etc.

dgillier — Thu, 17 Sep 2009 07:40:39 GMT

By curiosity, how did you connect masterlink to your rs232 interface, could you share your setup ?

Re: MasterLink ML specification, protocol, etc.

PhilLondon — Thu, 17 Sep 2009 07:24:50 GMT

Thanks Herwin,

It is actually going to be very useful for me, for a different project I am doing with the Beolink PC 2.

I'd like to ask you 2 things...

Is your software emulating Beoport in Option 0,2,4 or 6?

How did you reverse engineer the protocol? Is there a software on the PC that would allow me to spy on the communication between the Beoplayer software and the Beolink PC 2 box over USB.

Re: MasterLink ML specification, protocol, etc.

BeoAffinity — Thu, 17 Sep 2009 06:36:40 GMT

Hello herwin,

Thank you very much for your contribution and joining the forum to post an answer. I believe your code could be very useful for reverse-engineering the MasterLink protocol. A fleeting glimpse at your code reveals that the information which comes via USB is not exactly the data which floats on the ML bus. So the BeoLink PC2 processor does some data shifting, packaging, etc.

Bye,
Andy

Re: MasterLink ML specification, protocol, etc.

herwin — Wed, 16 Sep 2009 12:39:03 GMT

Hi,

Some years ago i made a linux program that can control the PC2. It can control your basic MP3 collection and do some nice things with it. I reverce engineed the protocol until i had no time anymore..

Maby it will help you.

http://sourceforge.net/projects/kpc2/develop

Herwin Jan

Re: MasterLink ML specification, protocol, etc.

BeoAffinity — Sat, 12 Sep 2009 04:04:01 GMT

@ Stefan and beojeff: Thank you for the good information.

Unfortunately, I don’t have access to BV7-40 MKIII, BS3 BeoLink Active or Passive with firmware version 1.6. But, some minutes ago I was at my local dealer to ask for a firmware update of an old BeoLink Passive which has version 1.4. I hope this could be done. The technician will be back on Monday – hopefully with good news.

With a simple hardware I connected the MasterLink to a Windows PC via a standard serial interface (RS232) to capture ML messages. Attached is a screenshot of a little windows application (ML-Analyzer was a suitable name for it), which shows some messages. Now it would be a good time to have a detailed specification. Anyone?

Andy